Practice Relating to Rule 145. Reprisals

Neither the 1949 Geneva Conventions nor the 1977 Additional Protocols provide a definition of “reprisal”. They are also silent on the requirements for legitimate reprisals in cases where they are not explicitly prohibited.
Geneva Conventions (1949)
The 1949 Geneva Conventions do not provide a definition of “reprisal”. They are also silent on the requirements for legitimate reprisals in cases where they are not explicitly prohibited. Common Article 1 of the 1949 Geneva Conventions provides: “The High Contracting Parties undertake to respect and to ensure respect for the present Convention in all circumstances.” 
Convention (I) for the Amelioration of the Condition of the Wounded and Sick in Armed Forces in the Field, Geneva, 12 August 1949, Article 1; Convention (II) for the Amelioration of the Condition of the Wounded, Sick and Shipwrecked Members of Armed Forces at Sea, Geneva, 12 August 1949, Article 1; Convention (III) relative to the Treatment of Prisoners of War, Geneva, 12 August 1949, Article 1; Convention (IV) relative to the Protection of Civilian Persons in Time of War, Geneva, 12 August 1949, Article 1.
Vienna Convention on the Law of Treaties
Article 60(5) of the 1969 Vienna Convention on the Law of Treaties states that the principle of reciprocity does not apply “to provisions relating to the protection of the human person contained in treaties of a humanitarian character, in particular to provisions prohibiting any form of reprisals against persons protected by such treaties”. 
Convention on the Law of Treaties, Vienna, 23 May 1969, Article 60(5).
Additional Protocol I
Additional Protocol I does not provide a definition of “reprisal”. It is also silent on the requirements for legitimate reprisals in cases where they are not explicitly prohibited. Article 1(1) of the 1977 Additional Protocol I provides: “The High Contracting Parties undertake to respect and to ensure respect for this Protocol in all circumstances.” 
Protocol Additional to the Geneva Conventions of 12 August 1949, and relating to the Protection of Victims of International Armed Conflicts (Protocol I), Geneva, 8 June 1977, Article 1(1). Article 1 was adopted by 87 votes in favour, one against and 11 abstentions. CDDH, Official Records, Vol. VI, CDDH/SR.36, 23 May 1977, p. 41.
Lieber Code
Article 28 of the 1863 Lieber Code provides:
Retaliation will, therefore, never be resorted to as a measure of mere revenge, but only as a means of protective retribution, and moreover, cautiously and unavoidably; that is to say, retaliation shall only be resorted to after careful inquiry into the real occurrence, and the character of the misdeeds that may demand retribution.
Unjust or inconsiderate retaliation removes the belligerents farther and farther from the mitigating rules of regular war, and by rapid steps leads them nearer to the internecine wars of savages. 
Instructions for the Government of Armies of the United States in the Field, prepared by Francis Lieber, promulgated as General Order No. 100 by President Abraham Lincoln, Washington D.C., 24 April 1863, Article 28.
ILC Draft Articles on State Responsibility
Article 49 of the 2001 ILC Draft Articles on State Responsibility, entitled “Object and limits of countermeasures”, provides:
1. An injured State may only take countermeasures against a State which is responsible for an internationally wrongful act in order to induce that State to comply with its obligations under Part Two [Articles 28–41].
2. Countermeasures are limited to the non-performance for the time being of international obligations of the State taking the measures towards the responsible State.
3. Countermeasures shall, as far as possible, be taken in such a way as to permit the resumption of performance of the obligations in question. 
Draft Articles on Responsibility of States for Internationally Wrongful Acts, adopted by the International Law Commission, reprinted in Report of the International Law Commission on the work of its fifty-third session, 23 April–1 June and 2 July–10 August 2001, UN Doc. A/56/10, 2001, Article 49.
Australia
Australia’s Commanders’ Guide (1994) defines a reprisal as “an act, otherwise unlawful under the international law regulating armed conflict, utilised for the purpose of coercing an adversary to stop violating the recognised rules of armed conflict”. 
Australia, Law of Armed Conflict, Commanders’ Guide, Australian Defence Force Publication, Operations Series, ADFP 37 Supplement 1 – Interim Edition, 7 March 1994, Glossary, p. xxiii.
The Guide further states:
Reprisals are otherwise illegal actions that are taken by one nation for the sole purpose of persuading another nation to comply with LOAC [law of armed conflict]. Nevertheless, because there is a risk that the conflict may escalate as a result, reprisals are rarely employed. 
Australia, Law of Armed Conflict, Commanders’ Guide, Australian Defence Force Publication, Operations Series, ADFP 37 Supplement 1 – Interim Edition, 7 March 1994, § 1211.
Australia
Australia’s Defence Force Manual (1994), in its table of definitions, defines the term “reprisal” as “an act, otherwise unlawful under the international law regulating armed conflict, utilised for the purpose of coercing an adversary to stop violating the recognised rules of armed conflict”. 
Australia, Manual on Law of Armed Conflict, Australian Defence Force Publication, Operations Series, ADFP 37 – Interim Edition, 1994, § 804.
The manual also states: “A reprisal is an otherwise illegal act done in response to a prior illegal act by the enemy. A reprisal aims to counter unlawful acts of warfare and to force the enemy to comply with the LOAC.” 
Australia, Manual on Law of Armed Conflict, Australian Defence Force Publication, Operations Series, ADFP 37 – Interim Edition, 1994, § 920.
The manual further states:
Reprisals are otherwise illegal actions that are taken by one nation for the sole purpose of persuading another nation to comply with the LOAC. Nevertheless, because there is a risk that the conflict may escalate as a result, reprisals are rarely employed. 
Australia, Manual on Law of Armed Conflict, Australian Defence Force Publication, Operations Series, ADFP 37 – Interim Edition, 1994, § 1310.
Australia
Australia’s LOAC Manual (2006) defines “reprisal” as: “An act, otherwise unlawful under the international law regulating armed conflict, utilised for the purpose of coercing an adversary to stop violating the recognised rules of armed conflict.” 
Australia, The Manual of the Law of Armed Conflict, Australian Defence Doctrine Publication 06.4, Australian Defence Headquarters, 11 May 2006, Glossary, p. 5.
The manual further states:
Nature of reprisals
13.17 Reprisals are acts which would normally be illegal, resorted to after the adverse party has itself carried out illegal acts and refused to desist when called upon to do so and issued with a warning that such action would be taken if the prior illegal act is not terminated. They are not retaliatory acts or simple acts of vengeance. Reprisals are, however, an extreme measure of coercion. Nevertheless, in the circumstances of armed conflict, reprisals, or the threat of reprisals, may sometimes provide the only practical means of inducing the adverse party to desist from its unlawful conduct.
Conditions for reprisal action
13.18 In order to qualify as a legitimate reprisal, an act must comply with the following conditions when employed:
• It must be in response to serious and manifestly unlawful acts, committed by an adverse government, its military commanders or combatants for whom the adversary is responsible.
• It must be for the purpose of compelling the adversary to observe the LOAC. Reprisals serve as an ultimate legal sanction or law enforcement mechanism. Thus, if one party to an armed conflict breaches the law but then expresses regret, declares that it will not be repeated and takes measures to punish those immediately responsible, then any action taken by another party in response to the original unlawful act cannot be justified as a reprisal.
• Reasonable notice must be given that reprisals will be taken. What degree of notice is required will depend upon the particular circumstances of the case.
• The victim of a violation must first exhaust other reasonable means of securing compliance before reprisals can be justified.
• A reprisal must be directed only against the personnel or property of an adversary.
• A reprisal must be in proportion to the original violation. Whilst a reprisal need not conform in kind to the act complained of, it may not significantly exceed the adverse party’s violation either in degree or effect. Effective but disproportionate acts cannot be justified as reprisals on the basis that only an excessive response will forestall further violations.
• It must be publicised. Since reprisals are undertaken to induce an adversary’s compliance with the LOAC any action taken as a reprisal must be announced as such and publicised so that the adversary is aware of the reason for the otherwise unlawful act and of its own obligation to abide by the law.
• As reprisals entail state responsibility, they must be authorised at the highest level of government.
• Reprisal action may not be taken or continued after the enemy has ceased to commit the conduct complained of. 
Australia, The Manual of the Law of Armed Conflict, Australian Defence Doctrine Publication 06.4, Australian Defence Headquarters, 11 May 2006, §§ 13.17–13.18; see also § 9.21.
The LOAC Manual (2006) replaces both the Defence Force Manual (1994) and the Commanders’ Guide (1994).
Belgium
Belgium’s Law of War Manual (1983) states:
Belligerent reprisals are actions which in themselves are contrary to the law of armed conflict but which are taken in response to violations committed by the adversary and to oblige him to comply with the law of armed conflict.
It adds that, when recourse is made to reprisals, “the following conditions must be fulfilled: 1) the adversary must have committed a violation duly established by the law of armed conflict”. 
Belgium, Droit Pénal et Disciplinaire Militaire et Droit de la Guerre, Deuxième Partie, Droit de la Guerre, Ecole Royale Militaire, par J. Maes, Chargé de cours, Avocat-général près la Cour Militaire, D/1983/1187/029, 1983, p. 35.
Benin
Benin’s Military Manual (1995) states: “As far as reprisals are concerned, under customary law, they are permitted to counter an unlawful act of warfare.” 
Benin, Le Droit de la Guerre, III fascicules, Forces Armées du Bénin, Ministère de la Défense nationale, 1995, Fascicule III, p. 13.
The manual also states: “Acts of vengeance are prohibited.” 
Benin, Le Droit de la Guerre, III fascicules, Forces Armées du Bénin, Ministère de la Défense nationale, 1995, Fascicule I, p. 17.
Canada
Canada’s LOAC Manual (1999) defines a reprisal as “an act, otherwise unlawful under the LOAC … utilized for the purpose of coercing an adversary to stop violating the recognized rules of armed conflict”. 
Canada, The Law of Armed Conflict at the Operational and Tactical Level, Office of the Judge Advocate General, 1999, Glossary, p. GL-17.
The manual also states:
In the event of serious or persistent breaches of the LOAC it may be necessary for the adverse party to resort to a reprisal in an attempt to terminate the illegality. A reprisal is an illegal act resorted to after the adverse party has performed illegal acts and has refused to stop after being called upon to do so. 
Canada, The Law of Armed Conflict at the Operational and Tactical Level, Office of the Judge Advocate General, 1999, p. 15-2, § 12.
The manual further states that a reprisal “is not a retaliatory act or a simple act of vengeance”. 
Canada, The Law of Armed Conflict at the Operational and Tactical Level, Office of the Judge Advocate General, 1999, p. 15-2, § 14.
The manual goes on to say:
To qualify as a reprisal, an act must satisfy the following conditions:
a. It must respond to serious violations and manifestly unlawful acts, committed by an adversary government, its military commanders, or combatants for whom the adversary is responsible;
b. It must be accomplished for the purpose of compelling the adversary to observe the LOAC. Reprisals can not be undertaken for revenge or punishment. They are directed against an adversary in order to induce compliance with LOAC. Thus, reprisals serve as a law enforcement mechanism. Above all, reprisals are justifiable only to force an adversary to stop its illegal activity. If, for example, a party to an armed conflict commits a breach of law but follows that violation with an expression of regret and promise that it will not be repeated, and even takes steps to punish those responsible, then the action taken by another party to “redress” the situation cannot be justified as a lawful reprisal;
c. There must be reasonable notice that reprisals will be taken. What degree of notice is required will depend upon the particular circumstances of each case. Notice is normally given after the violation but may, in appropriate circumstances, predate the violation. An example is an appeal to the transgressor to cease its offending conduct and punish those responsible. Thus, such an appeal may serve both as a plea for compliance and a notice to the adversary that reprisals will be taken;
g. It must be publicized. Since reprisals are undertaken to induce an adversary’s compliance with the recognized rules of LOAC, any action taken as a reprisal must be announced as a reprisal and publicized so that the adversary is aware of its obligation to abide by the law. 
Canada, The Law of Armed Conflict at the Operational and Tactical Level, Office of the Judge Advocate General, 1999, p. 15-2, § 17.
Canada
Canada’s LOAC Manual (2001) states in its chapter entitled “Preventative and enforcement measures and the role of protecting powers”:
1. In the event of serious or persistent breaches of the LOAC it may be necessary for the adverse party to resort to a reprisal in an attempt to terminate the illegality. [A] reprisal is an illegal act resorted to after the adverse party has performed illegal acts and has refused to stop after being called upon to do so.
3. Reprisal is not a retaliatory act or a simple act of vengeance. It must be proportionate to the original wrongdoing, and must be terminated as soon as the original wrongdoer ceases the illegal actions …
6. To qualify as a reprisal, an act must satisfy the following conditions:
a. It must respond to serious violations and manifestly unlawful acts committed by an adversary government, its military commanders or combatants for whom the adversary is responsible;
b. It must be accomplished for the purpose of compelling the adversary to observe the LOAC.
Reprisals cannot be undertaken for revenge or punishment. They are directed against an adversary in order to induce compliance with the LOAC. Thus, reprisals serve as a law enforcement mechanism. Above all, reprisals are justifiable only to force an adversary to stop its illegal activity.
If, for example, a party to an armed conflict commits a breach of law but follows that violation with an expression of regret and promise that it will not be repeated, and even takes steps to punish those responsible, then any action taken by another party to “redress” the situation cannot be justified as a lawful reprisal;
c. There must be reasonable notice that reprisals will be taken. What degree of notice is required will depend upon the particular circumstances of each case. Notice is normally given after the violation but may, in appropriate circumstances, predate the violation. An example of notice is an appeal to the transgressor to cease its offending conduct and punish those responsible. Thus, such an appeal may serve both as a plea for compliance and a notice to the adversary that reprisals will be undertaken;
g. It must be publicized. Since reprisals are undertaken to induce an adversary’s compliance with the recognized rules of LOAC, any action taken as a reprisal must be announced as a reprisal and publicized so that the adversary is aware of its obligation to abide by the law. 
Canada, The Law of Armed Conflict at the Operational and Tactical Levels, Office of the Judge Advocate General, 13 August 2001, § 1507.1, 3, 6.a–c and g.
In its glossary, the manual defines reprisal as: “An act, otherwise unlawful under the LOAC conflict, utilized for the purpose of coercing an adversary to stop violating the recognized rules of armed conflict.” 
Canada, The Law of Armed Conflict at the Operational and Tactical Levels, Office of the Judge Advocate General, 13 August 2001, Glossary, pp. GL-16 and GL-17.
Central African Republic
The Central African Republic’s Instructor’s Manual (1999) states in Volume 3 (Instruction for non-commissioned officers studying for the level 1 and 2 certificates and for future officers of the criminal police): “Reprisals are permitted under customary law if they are made in response to an unlawful act of war. Reprisals may be made only if: … directed only against combatants and military objectives.” 
Central African Republic, Le Droit de la Guerre, Fascicule No. 3: Formation pour l’obtention du Brevet d’Armes No. 1, du Brevet d’Armes No. 2 et le stage d’Officier de Police Judiciaire (OPJ), Ministère de la Défense, Forces Armées Centrafricaines, 1999, Chapter I, Section I.
The manual also states: “The following prohibitions must be respected: … launching reprisals against protected persons and objects”. 
Central African Republic, Le Droit de la Guerre, Fascicule No. 3: Formation pour l’obtention du Brevet d’Armes No. 1, du Brevet d’Armes No. 2 et le stage d’Officier de Police Judiciaire (OPJ), Ministère de la Défense, Forces Armées Centrafricaines, 1999, Chapter III, Section I.
Central African Republic
The Central African Republic’s Disciplinary Regulations of the Armed Forces (2009) states: “During combat, it is also prohibited for servicemen to … use reprisals”. 
Central African Republic, Décret 09.411 portant règlement de discipline générale dans les Armées, Ministre de la Défense Nationale, des Anciens Combattants, des Victimes de Guerre, du Désarmement et de la Restructuration de l’Armée, 10 December 2009, Article 12(11).
Chad
Chad’s Instructor’s Manual (2006) requires soldiers to “refrain from any act of vengeance”. 
Chad, Droit international humanitaire, Manuel de l’instructeur en vigueur dans les forces armées et de sécurité, Ministère de la Défense, Présidence de la République, Etat-major des Armées, 2006, p. 26; see also pp. 15 and 47.
Congo
The Congo’s Disciplinary Regulations (1986) states: “It is prohibited [to military personnel in combat] to commit reprisals.” 
Congo, Décret No. 86/057 du 14 janvier 1986 portant Règlement du Service dans l’Armée Populaire Nationale, 1986, Article 32(2).
Côte d’Ivoire
Côte d’Ivoire’s Teaching Manual (2007) provides in Book III, Volume 2 (Instruction of second-year trainee officers):
III.1. Collective responsibility
Collective responsibility of a belligerent party for a violation of the law of armed conflicts [LOAC] takes several forms.
- Reprisal measures taken by one belligerent party constitute the second type of collective responsibility. This is an intentional violation of a given rule of the law of armed conflicts, committed by one of the parties to the conflict with the aim of forcing the authorities of the adverse party to end a policy of violation of that same rule or another provision.
Customary law regards measures of reprisal taken by a belligerent party as one of the lawful means intended to enforce the application of the law.
However, since these measures often lead to an escalation of the violence and generally strike persons who are not the true culprits, the law of reprisals of belligerent parties has progressively been restricted. Thus, reprisal measures against protected persons and objects are the subject of an express prohibition in the four 1949 Geneva Conventions.
The main interest of the diverse modalities relating to the responsibility of the State probably lies in their dissuasive effect. The fact that every violation of the law of armed conflicts engages the responsibility of the State can prompt the authorities to respect the provisions of the LOAC. 
Côte d’Ivoire, Droit de la guerre, Manuel d’instruction, Livre III, Tome 2: Instruction de l’élève officier d’active de 2ème année, Manuel de l’instructeur, Ministère de la Défense, Forces Armées Nationales, November 2007, pp. 37–38 ; see also Droit de la guerre, Manuel d’instruction, Livre IV: Instruction du chef de section et du commandant de compagnie, Manuel de l’élève, Ministère de la Défense, Forces Armées Nationales, November 2007, pp. 67–68.
Croatia
Croatia’s LOAC Compendium (1991) defines a reprisal as a “direct law enforcement procedure” and as a “breach of the L.O.W. [laws of war] for the purpose of terminating enemy violations”. It also states that a condition for a reprisal is that it is directed “against [a] serious, manifest and deliberate breach of [the] L.O.W.”. 
Croatia, Compendium “Law of Armed Conflicts”, Republic of Croatia, Ministry of Defence, 1991, p. 19.
Djibouti
Djibouti’s Disciplinary Regulations (1982) states: “It is prohibited for combatants to … [engage in] reprisals”. 
Djibouti, Décret no. 82-028/PR/DEF du 5 mai 1982 portant règlement de la discipline générale dans les Forces armées, Article 30(3).
Ecuador
Ecuador’s Naval Manual (1989) states:
A reprisal is an enforcement measure under the law of armed conflict consisting of an act which would otherwise be unlawful but which is justified as a response to the unlawful acts of an enemy. The sole purpose of a reprisal is to induce the enemy to cease its illegal activity and to comply with the law of armed conflict. 
Ecuador, Aspectos Importantes del Derecho Internacional Marítimo que Deben Tener Presente los Comandantes de los Buques, Academia de Guerra Naval, 1989, § 6.2.3.
The manual further states:
To be valid, a reprisal action must conform to the following criteria:
2. It must respond to illegal acts of warfare committed by an adversary government, its military commanders, or combatants for which the adversary is responsible. Anticipatory reprisal is not authorized.
4. Its purpose must be to cause the enemy to cease its unlawful activity. Therefore, acts taken in reprisal should be brought to the attention of the enemy in order to achieve maximum effectiveness. Reprisal must never be taken for revenge. 
Ecuador, Aspectos Importantes del Derecho Internacional Marítimo que Deben Tener Presente los Comandantes de los Buques, Academia de Guerra Naval, 1989, § 6.2.3.1.
France
France’s LOAC Manual (2001) states:
Reprisals aim to obtain the cessation of a violation committed by the enemy … The United Nations Charter permitting the use of force only in case of aggression, reprisals are permitted only in response to a previous attack. They must always aim at a military objective and be preceded by a warning. One must not confuse reprisals, retaliation and vengeance. Vengeance is always prohibited. 
France, Manuel de droit des conflits armés, Ministère de la Défense, Direction des Affaires Juridiques, Sous-Direction du droit international humanitaire et du droit européen, Bureau du droit des conflits armés, 2001, pp. 108 and 109.
Germany
Germany’s Soldiers’ Manual (1991) states: “Reprisals are measures of retaliation, as such adverse to international public law, which a State may, as an exception, use against another State in order to induce the latter to stop the violation of international public law.” 
Germany, Taschenkarte, Humanitäres Völkerrecht in bewaffneten Konflikten – Grundsätze, Bearbeitet nach ZDv 15/2, Humanitäres Völkerrecht in bewaffneten Konflikten – Handbuch, Zentrum Innere Führung, June 1991, p. 2.
Germany
Germany’s Military Manual (1992) states: “Reprisals are retaliatory measures normally contrary to international law taken by one party to the conflict in order to stop the adversary from violating international law.” 
Germany, Humanitarian Law in Armed Conflicts – Manual, DSK VV207320067, edited by The Federal Ministry of Defence of the Federal Republic of Germany, VR II 3, August 1992, English translation of ZDv 15/2, Humanitäres Völkerrecht in bewaffneten KonfliktenHandbuch, August 1992, § 476.
The manual further states:
The use of reprisals can cause an adversary acting contrary to international law to stop his violations of the law. Reprisals are permissible only in exceptional cases and only for the purpose of enforcing compliance with international law. 
Germany, Humanitarian Law in Armed Conflicts – Manual, DSK VV207320067, edited by The Federal Ministry of Defence of the Federal Republic of Germany, VR II 3, August 1992, English translation of ZDv 15/2, Humanitäres Völkerrecht in bewaffneten KonfliktenHandbuch, August 1992, § 1206.
Germany
Germany’s IHL Manual (1996) provides: “Reprisals are compulsory measures which one State may exceptionally use against another State in order to cause the latter to stop violations of international public law.” 
Germany, ZDv 15/1, Humanitäres Völkerrecht in bewaffneten Konflikten – Grundsätze, DSK VV230120023, Bundesministerium der Verteidigung, June 1996, § 318.
Germany
Germany’s Soldiers’ Manual (2006) states:
Reprisals are measures of retaliation, as such adverse to public international law, which a State may, as an exception, use against another State in order to induce the latter to stop violations of public international law. 
Germany, Druckschrift Einsatz Nr. 03, Humanitäres Völkerrecht in bewaffneten Konflikten – Grundsätze, Erarbeitet nach ZDv 15/2, Humanitäres Völkerrecht in bewaffneten Konflikten – Handbuch, DSK SF009320187, Bundesministerium der Verteidigung, R II 3, August 2006, p. 2.
Guinea
Guinea’s Soldier’s Manual (2010), under the heading “Civilians”, states that “acts of vengeance are … prohibited.” 
Guinea, Soldier’s Manual, Ministry of National Defence, 2010, p. 10; see also p. 15.
Guinea
Guinea’s Disciplinary Regulations (2012) states: “Military personnel in combat are prohibited from … engaging in reprisals”. 
Guinea, Règlement de Service dans les Forces Armées, Volume 1: Règlement de Discipline Générale (Service Regulations in the Armed Forces, Volume 1: General Discipline Regulations), 2012 edition, Ministère de la Défense Nationale, approved by Presidential Decree No. D 293/PRG/SGG/2012, 6 December 2012, Article 12(b).
Hungary
Hungary’s Military Manual (1992) defines a reprisal as a “direct law enforcement procedure” and as a “breach of the L.O.W. [laws of war] for the purpose of terminating enemy violations”. It also provides that a condition for a reprisal is that it is directed “against [a] serious, manifest and deliberate breach of [the] L.O.W.”. 
Hungary, A Hadijog, Jegyzet a Katonai, Föiskolák Hallgatói Részére, Magyar Honvédség Szolnoki Repülötiszti Föiskola, 1992, p. 35.
Indonesia
Indonesia’s Air Force Manual (1990) provides:
In principle, reprisals in warfare are prohibited, i.e. an act which categorize[s] against the laws of war and aim[s] to [answer to] the breach of the laws of war treaties committed by the adverse party. The reprisal could be allowed if, although it has been warned, the adverse party still continue[s] to violate the laws of war. 
Indonesia, The Basics of International Humanitarian Law in Air Warfare, Indonesian Air Force, 1990, § 15(c).
Italy
Italy’s IHL Manual (1991) states:
The purpose of a reprisal is to induce the enemy to respect its obligations under international law and can be carried out either by means of acts similar to those illegally committed or by means of acts of a different nature. Therefore, a reprisal does not have the nature of a punishment, but is only a measure of direct coercion in inducing the enemy to respect its obligations towards [Italy] … Given the nature and scope of a reprisal, it can, as a general rule, only be directed against the belligerent that violated the laws of war with regard to [Italy]. 
Italy, Manuale di diritto umanitario, Introduzione e Volume I, Usi e convenzioni di Guerra, SMD-G-014, Stato Maggiore della Difesa, I Reparto, Ufficio Addestramento e Regolamenti, Rome, 1991, Vol. I, § 23.
The manual further states that the Italian Government has declared in international fora that, in response to grave and systematic violations of the obligations relative to the protection of the civilian population and civilian objects, Italy will react by every measure permitted under international law to prevent the recurrence of such violations. 
Italy, Manuale di diritto umanitario, Introduzione e Volume I, Usi e convenzioni di Guerra, SMD-G-014, Stato Maggiore della Difesa, I Reparto, Ufficio Addestramento e Regolamenti, Rome, 1991, Vol. I, § 26.
Kenya
Kenya’s LOAC Manual (1997) states:
Under customary law, reprisals are permitted to counter unlawful acts of warfare. They can only be taken if:
–they are intended to secure legitimate warfare;
–… they are carried out only against combatants and military objectives.
Reprisals are an unsatisfactory way of enforcing the law. They tend to be used as an excuse for illegal methods of warfare and carry a danger of escalation through repeated reprisals and counter reprisals. 
Kenya, Law of Armed Conflict, Military Basic Course (ORS), 4 Précis, The School of Military Police, 1997, Précis No. 4, p. 4.
Mali
Mali’s Army Regulations (1979) states that it is prohibited for military personnel in combat “to commit reprisals”. 
Mali, Règlement du Service dans l’Armée, 1ère Partie: Discipline Générale, Ministère de la Défense Nationale, 1979, Article 36.
Mexico
Mexico’s Army and Air Force Manual (2009) states: “During the course of a war, a State may take reprisals against the enemy when it has violated international law only for the purpose of deterring it from doing it again in the future.” 
Mexico, Manual de Derecho Internacional Humanitario para el Ejército y la Fuerza Área Mexicanos, Ministry of National Defence, June 2009, § 384.
Morocco
Morocco’s Disciplinary Regulations (1974), in a provision entitled “Laws and customs of war” dealing with the duties of and prohibitions for combatants, states: “It is prohibited to soldiers in combat: … to take hostages, to engage in reprisals or collective punishments”. 
Morocco, Règlement de Discipline Général dans les Forces Armées Royales, Dahir No. 1-74-383 du 15 rejeb 1394, 5 August 1974, Article 25(2).
Netherlands
The Military Manual (1993) of the Netherlands states:
A reprisal is a measure which by itself constitutes a violation of the rules of humanitarian law of war but which is justified by the fact that it aims to force a state to put an end to previously committed violations of humanitarian law of war and to comply with the law. 
Netherlands, Toepassing Humanitair Oorlogsrecht, Voorschift No. 27-412/1, Koninklijke Landmacht, Ministerie van Defensie, 1993, p. IV-5; see also p. IX-2.
The manual, referring to customary law, further states that reprisals are in principle allowed, provided that a number of conditions are fulfilled:
–Reprisals are only lawful when they aim at a violation previously committed by the adverse party the existence of which must be properly determined.
–Reprisals against reprisals are prohibited. 
Netherlands, Toepassing Humanitair Oorlogsrecht, Voorschift No. 27-412/1, Koninklijke Landmacht, Ministerie van Defensie, 1993, p. IV-5.
The manual concludes: “The freedom of states which have ratified Additional Protocol I to take recourse to reprisals is very limited.” 
Netherlands, Toepassing Humanitair Oorlogsrecht, Voorschift No. 27-412/1, Koninklijke Landmacht, Ministerie van Defensie, 1993, p. IV-6.
Netherlands
The Military Manual (2005) of the Netherlands states:
Section 7 - Reprisals
0422. Reprisals mean a measure or action which itself entails breach of the rules of the humanitarian law of war, but is justified because it serves to compel a State put an end to previously committed illegalities or breaches of the humanitarian law of war, and to behave in accordance with the rules of the law.
0423. On the basis of customary law, it used to be assumed that reprisals were allowed in principle by the law of war, provided that a number of conditions were met:
- reprisals are only permitted on grounds of, and directed against, an illegality previously committed by the adversary, which must be duly proven;
- reprisals against reprisals are forbidden. 
Netherlands, Humanitair Oorlogsrecht: Handleiding, Voorschift No. 27-412, Koninklijke Landmacht, Militair Juridische Dienst, 2005, §§ 0422–0423; see also § 0224(f).
The manual further states:
[P]ersons and property against which reprisals cannot be carried out is that the scope for reprisals by States which have ratified AP I [1977 Additional Protocol I] is very limited. Reprisals are now only possible against combatants and military targets. Whereas the power to carry out reprisals has been and, in part, still is valid as a way of forcing the adversary to obey the rules of the humanitarian law of war, the conclusion is that this way of achieving compliance with the law of war has become less significant. 
Netherlands, Humanitair Oorlogsrecht: Handleiding, Voorschift No. 27-412, Koninklijke Landmacht, Militair Juridische Dienst, 2005, § 0425.
In its chapter on the prevention and punishment of war crimes, the manual states:
1112. Reprisals
A reprisal means a measure or act which, in itself, entails violation of the rules of the humanitarian law of war, but which is justified by seeking to compel a State to end previous irregularities or breaches of the humanitarian law of war and to behave in accordance with the rules of the law.
1113. Reprisals are only permitted in exceptional cases, and then only after a decision by the political leadership. 
Netherlands, Humanitair Oorlogsrecht: Handleiding, Voorschift No. 27-412, Koninklijke Landmacht, Militair Juridische Dienst, 2005, §§ 1112–1113.
In its chapter on peace operations, the manual states that “the conduct of reprisals is tied to (very) strict rules”. 
Netherlands, Humanitair Oorlogsrecht: Handleiding, Voorschift No. 27-412, Koninklijke Landmacht, Militair Juridische Dienst, 2005, § 1217.
New Zealand
New Zealand’s Military Manual (1992) states:
A reprisal is an illegal act resorted to after the adverse Party has himself indulged in illegal acts and refused to desist from them after being called upon to do so. The reprisal is not a retaliatory act or simple act of vengeance. 
New Zealand, Interim Law of Armed Conflict Manual, DM 112, New Zealand Defence Force, Headquarters, Directorate of Legal Services, Wellington, November 1992, § 1606(1).
The manual further states:
In order to be considered a reprisal, an act must have certain characteristics:
a) It must respond to grave and manifestly unlawful acts committed by an adverse government, its military commanders, or combatants for whom the adversary is responsible.
b) It must be for the purpose of compelling the adverse Party to observe the law of armed conflict. Reprisals cannot be undertaken for the law of armed revenge, spite or punishment. Rather, they are directed against an adverse Party in order to induce him to refrain from further violations of the law of armed conflict. Thus, reprisals serve as an ultimate legal sanction or law enforcement mechanism. Above all, they are justifiable only to force an adverse Party to stop its illegal activity. If, for example, one Party to an armed conflict commits a breach of law but follows that violation with an expression of regret and promise that it will not be repeated, and even takes steps to punish those immediately responsible, the other Party cannot justify a lawful reprisal as the appropriate action to “right” the situation.
c) There must be reasonable notice that reprisals will be taken. What degree of notice is required will depend on the particular circumstances of each case. Notice is normally given after the violation but may, in appropriate circumstances, predate the violation. An example of notice is an appeal to the transgressor to cease its offending conduct and punish those responsible. Thus, such an appeal may serve both as a plea for compliance and a notice to the adverse Party that reprisals will be undertaken.
g) It must be publicized. Since reprisals are undertaken to induce an adverse Party’s compliance with the recognized rules of armed conflict, any action taken as a reprisal must be announced as a reprisal and publicized so that the adverse Party is aware of its obligation to abide by the law. 
New Zealand, Interim Law of Armed Conflict Manual, DM 112, New Zealand Defence Force, Headquarters, Directorate of Legal Services, Wellington, November 1992, § 1606(4).
Nigeria
Nigeria’s Military Manual (1994), in a section dealing with the 1977 Geneva Convention I and those upon whom reprisals are prohibited, states:
[In the cases where reprisals are prohibited], a belligerent party cannot claim a right to set aside the rules of the convention in order to induce the enemy to return to an attitude of respect for the law of armed conflict. 
Nigeria, International Humanitarian Law (IHL), Directorate of Legal Services, Nigerian Army, 1994, p. 14, § 5.
Peru
Peru’s IHL Manual (2004) states:
Reprisals consist of giving a warning (military action) or putting pressure on the enemy to force it to stop committing unlawful acts of war and respect international humanitarian law.
(1) Reprisals are a reaction to a violation of international humanitarian law committed by the enemy, the purpose of which is to put a stop to the violation. 
Peru, Manual de Derecho Internacional Humanitario para las Fuerzas Armadas, Resolución Ministerial Nº 1394-2004-DE/CCFFAA/CDIH-FFAA, Lima, 1 December 2004, § 25.c.(1).
Peru
Peru’s IHL and Human Rights Manual (2010) states:
Reprisals consist of giving a warning (military action) or putting pressure on the enemy to force it to stop committing unlawful acts of war and to respect international humanitarian law.
(1) Reprisals are a reaction to a violation of international humanitarian law committed by the enemy, the purpose of which is to put a stop to the violation. 
Peru, Manual de Derecho Internacional Humanitario y Derechos Humanos para las Fuerzas Armadas, Resolución Ministerial No. 049-2010/DE/VPD, Lima, 21 May 2010, § 29(c)(1), p. 234.
Philippines
The Soldier’s Rules (1989) of the Philippines states that a soldier must “abstain from all acts of vengeance”. 
Philippines, Soldier’s Rules, in Handbook on Discipline, Annex C(I), General Headquarters, Armed Forces of the Philippines, Camp General Emilio Aguinaldo, Quezon City, 1989, §§ 8 and 9.
South Africa
South Africa’s LOAC Manual (1996) states:
A reprisal is an otherwise illegal act in response to a prior illegal act by the enemy. The purpose of a reprisal is to get the enemy to adhere to the law of war. Reprisals are only permitted according to strict criteria. 
South Africa, Presentation on the South African Approach to International Humanitarian Law, Appendix A, Chapter 4: International Humanitarian Law (The Law of Armed Conflict), National Defence Force, 1996, § 34(e).
[emphasis in original]
South Africa
South Africa’s Revised Civic Education Manual (2004) states:
A reprisal is an otherwise illegal act in response to a prior illegal act by the enemy. The purpose of a reprisal is to get the enemy to adhere to the law of war. Reprisals are only permitted according to strict criteria. 
South Africa, Revised Civic Education Manual, South African National Defence Force, 2004, Chapter 4, § 56(e).
[emphasis in original]
South Africa
South Africa’s LOAC Teaching Manual (2008) states:
Reprisals
- In general it can be said that it is lawful for States to take reprisal actions, but not for individual soldiers to do so.
- Reprisals are actions which would normally have been unlawful under international law, but which become lawful in order to stop the unlawful act of another Party to the conflict.
- The LOAC [law of armed conflict] prohibits reprisals against the following:
- Civilians, civilian objects and the civilian population;
- POW [prisoners of war];
- Specifically protected persons and objects;
- Objects indispensable for the survival of the civilian population;
- The natural environment.
- Reprisals have been defined as acts of retaliation in the form of conduct which would otherwise be unlawful, taken as a last resort by one Party to the conflict against enemy personnel or property in retort to violations of LOAC committed by the other party for the sole purpose of enforcing future compliance with the rules of the LOAC. [US Army Field Manual FM-2710, paragraph 497, US v Oldendorf, 4 Trials of War Criminals before the Nuremberg Military Tribunals, 493 (1950)].
- Reprisal actions should only be taken if the enemy breach of the LOAC is deliberate and of a serious nature. 
South Africa, Advanced Law of Armed Conflict Teaching Manual, School of Military Justice, 1 April 2008, as amended to 25 October 2013, Learning Unit 3, p. 194.
Spain
Spain’s LOAC Manual (1996) defines a reprisal as “a violation of the law of war, committed in response to the violation of the said law committed by the enemy”. Among the conditions which must be fulfilled for the lawful taking of reprisals, the manual states: “The action of the enemy must constitute a grave, manifest and deliberate violation of the law of war.” It further emphasizes that reprisals are only permitted if authorization is given by the international conventions.  
Spain, Orientaciones. El Derecho de los Conflictos Armados, Publicación OR7-004, 2 Tomos, aprobado por el Estado Mayor del Ejército, Division de Operaciones, 18 March 1996, Vol. I, § 3.3.c.(5)(a).
In another chapter, the manual states: “The fear of reprisals can influence belligerent parties and induce them to respect the International Conventions. Reprisals are authorized only in case of a violation of the law of war.” 
Spain, Orientaciones. El Derecho de los Conflictos Armados, Publicación OR7-004, 2 Tomos, aprobado por el Estado Mayor del Ejército, Division de Operaciones, 18 March 1996, Vol. I, § 11.10.c.
Spain
Spain’s LOAC Manual (2007) states: “Reprisals are in violation of the law of armed conflict when used in response to an enemy violation of this body of law … [They] can only be used in truly exceptional cases.” 
Spain, Orientaciones. El Derecho de los Conflictos Armados, Tomo 1, Publicación OR7–004, (Edición Segunda), Mando de Adiestramiento y Doctrina, Dirección de Doctrina, Orgánica y Materiales, 2 November 2007, § 3.3.c.(5).
The manual also states:
A State can, exceptionally, take measures against another State that commits an internationally unlawful act against it, with a view to pressuring it to comply with its international obligations. …
Fear of reprisals can influence the parties to the conflict to respect international conventions. 
Spain, Orientaciones. El Derecho de los Conflictos Armados, Tomo 1, Publicación OR7–004, (Edición Segunda), Mando de Adiestramiento y Doctrina, Dirección de Doctrina, Orgánica y Materiales, 2 November 2007, § 11.8.c.
The manual also states: “Reprisals … to make the enemy comply with the law of armed conflict … must focus solely on this ultimate goal. Some reprisals are specifically prohibited, such as those directed against protected persons.” 
Spain, Orientaciones. El Derecho de los Conflictos Armados, Tomo 1, Publicación OR7–004, (Edición Segunda), Mando de Adiestramiento y Doctrina, Dirección de Doctrina, Orgánica y Materiales, 2 November 2007, § 2.3.b.(6).
The manual further states: “Abstain from all acts of vengeance.” 
Spain, Orientaciones. El Derecho de los Conflictos Armados, Tomo 1, Publicación OR7–004, (Edición Segunda), Mando de Adiestramiento y Doctrina, Dirección de Doctrina, Orgánica y Materiales, 2 November 2007, § 10.3.e.(1).
Sweden
Sweden’s IHL Manual (1991) states:
Reprisals very seldom achieve their intended aim – the return of a wrongdoer to compliance with international law. In most cases, use of reprisals has, instead, led to a serious increase of suffering and losses among civilians. For these reasons, Sweden has, during the [CDDH] and elsewhere, worked for a strict limitation to the right to reprisal. Under Additional Protocol I, reprisals are permitted only against military personnel. A state acceding to Additional Protocol I thereby accepts a limitation of its freedom to employ reprisals. The [Swedish International Humanitarian Law] Committee believes that this involves a considerable humanitarian advance. 
Sweden, International Humanitarian Law in Armed Conflict, with reference to the Swedish Total Defence System, Swedish Ministry of Defence, January 1991, Section 3.5, p. 89.
Switzerland
Switzerland’s Basic Military Manual (1987) states: “Reprisals are measures contrary to international law taken by one of the belligerents to punish unlawful acts committed by the enemy Power and to bring them to a halt.” 
Switzerland, Lois et coutumes de la guerre (Extrait et commentaire), Règlement 51.7/II f, Armée Suisse, 1987, Article 197(1).
Switzerland
Switzerland’s Aide-Memoire on the Ten Basic Rules of the Law of Armed Conflict (2005) states: “All forms of retaliation are prohibited.” 
Switzerland, The Ten Basic Rules of the Law of Armed Conflict, Aide-memoire 51.007/IIIe, Swiss Army, issued based on Article 10 of the Ordinance for Organization of the Federal Department for Defence, Civil Protection and Sports dated 7 March 2003, entry into force on 1 July 2005, Rule 3.
Switzerland
Switzerland’s Regulation on Legal Bases for Conduct during an Engagement (2005) states: “Indiscriminate attacks, i.e. attacks which cannot distinguish between protected persons/objects and military objectives, as well as attacks directed against protected persons/objects or acts of revenge are prohibited in any place and at any time.” 
Switzerland, Bases légales du comportement à l’engagement (BCE), Règlement 51.007/IVf, Swiss Army, issued based on Article 10 of the Ordinance on the Organization of the Federal Department for Defence, Civil Protection and Sports of 7 March 2003, entry into force on 1 July 2005, § 225.
(emphasis in original)
Togo
Togo’s Military Manual (1996) states: “As far as reprisals are concerned, under customary law, they are permitted to counter an unlawful act of warfare.” 
Togo, Le Droit de la Guerre, III fascicules, Etat-major Général des Forces Armées Togolaises, Ministère de la Défense nationale, 1996, Fascicule III, p. 13.
It also states: “Acts of vengeance are prohibited.” 
Togo, Le Droit de la Guerre, III fascicules, Etat-major Général des Forces Armées Togolaises, Ministère de la Défense nationale, 1996, Fascicule I, p. 18.
Ukraine
Ukraine’s IHL Manual (2004) defines “Reprisals” as: “violations of international humanitarian law in response to violations by the enemy State in order to stop unlawful actions by the opponent party to the conflict”. 
Ukraine, Manual on the Application of IHL Rules, Ministry of Defence, 11 September 2004, § 1.2.18.
United Kingdom of Great Britain and Northern Ireland
The UK Military Manual (1958) states: “Reprisals between belligerents are acts of retaliation for illegitimate acts of warfare. One of their objects is to cause the enemy to comply in future with the recognised laws of war. Reprisals are by custom admissible as a means of securing legitimate warfare.” It further states: “The illegitimate acts in respect of which reprisals are admissible may be committed by a government, by its military commanders, or by some person or persons whom it is impossible, for the time being, to apprehend, try and punish.” 
United Kingdom, The Law of War on Land being Part III of the Manual of Military Law, The War Office, HMSO, 1958, §§ 642 and 643.
The manual also notes:
Reprisals are an extreme measure of coercion, because in most cases they inflict suffering upon innocent individuals. Nevertheless, in the circumstances of war, they often provide the only remedy as a punishment, as a deterrent and as a means of inducing the enemy to desist from his unlawful conduct. 
United Kingdom, The Law of War on Land being Part III of the Manual of Military Law, The War Office, HMSO, 1958, § 644.
In addition, in a footnote on a provision regarding the procedure before recourse to reprisals is made, the manual states: “A certain caution should be exercised before deciding to institute reprisals, as in some cases counter-reprisals may follow, thus defeating the purpose of the original reprisals.” 
United Kingdom, The Law of War on Land being Part III of the Manual of Military Law, The War Office, HMSO, 1958, § 646, footnote 2.
United Kingdom of Great Britain and Northern Ireland
The UK LOAC Pamphlet (1981) states: “Under customary law reprisals are permitted to counter unlawful acts of warfare. They can only be taken if: a. they are intended to secure legitimate warfare.” It also states: “Reprisals are an unsatisfactory way of enforcing the law. They tend to be used as an excuse for illegal methods of warfare with a danger of escalation through repeated reprisals and counter-reprisals.” However, the manual also states:
The United Kingdom reserves the right to take proportionate reprisals against an enemy’s civilian population or civilian objects where the enemy has attacked our own civilians or civilian objects in violation of [the 1977 Additional Protocol I].  
United Kingdom, The Law of Armed Conflict, D/DAT/13/35/66, Army Code 71130 (Revised 1981), Ministry of Defence, prepared under the Direction of The Chief of the General Staff, 1981, Section 4, p. 17, §§ 14, 15 and 17.
United Kingdom of Great Britain and Northern Ireland
The UK LOAC Manual (2004) states:
Enforcement of the law of armed conflict can involve a wide variety of measures. “Enforcement” is taken here to mean action to ensure observance of the law and also action that may be taken following alleged or actual violations. Action aimed at effective enforcement of the law can include, but is not limited to:
k. Reprisals by an aggrieved state. 
United Kingdom, The Manual of the Law of Armed Conflict, Ministry of Defence, 1 July 2004, § 16.1.
The manual further states:
16.16. Reprisals are extreme measures to enforce compliance with the law of armed conflict by the adverse party. They can involve acts which would normally be illegal, resorted to after the adverse party has itself carried out illegal acts and refused to desist when called upon to do so. They are not retaliatory acts or simple acts of vengeance. Reprisals are, however, an extreme measure of coercion, because in most cases they inflict suffering upon innocent individuals. Nevertheless, in the circumstances of armed conflict, reprisals, or the threat of reprisals, may sometimes provide the only practical means of inducing the adverse party to desist from its unlawful conduct.
Conditions for reprisal action
16.17. In order to qualify as a legitimate reprisal, an act must comply with the following conditions when employed:
a. It must be in response to serious and manifestly unlawful acts, committed by an adverse government, its military commanders or combatants for whom the adversary is responsible;
b. It must be for the purpose of compelling the adversary to observe the law of armed conflict. Reprisals serve as an ultimate legal sanction or law enforcement mechanism. Thus, if one party to an armed conflict breaches the law but then expresses regret, declares that it will not be repeated and takes measures to punish those immediately responsible, then any action taken by another party in response to the original unlawful act cannot be justified as a reprisal;
e. A reprisal must be directed against the personnel or property of an adversary;
g. It must be publicized. Since reprisals are undertaken to induce an adversary’s compliance with the laws of armed conflict, any action taken as a reprisal must be announced as such and publicized so that the adversary is aware of the reason for the otherwise unlawful act and of its own obligation to abide by the law. 
United Kingdom, The Manual of the Law of Armed Conflict, Ministry of Defence, 1 July 2004, §§ 16.16–16.17.
The manual also restates the interpretative declaration made by the UK upon ratification of the 1977 Additional Protocol I (see infra). 
United Kingdom, The Manual of the Law of Armed Conflict, Ministry of Defence, 1 July 2004, § 16.19.1.
United States of America
The US Field Manual (1956) states:
(a) Definition. Reprisals are acts of retaliation in the form of conduct which would otherwise be unlawful, resorted to by one belligerent against enemy personnel or property for acts of warfare committed by the other belligerent in violation of the law of war, for the purpose of enforcing future compliance with the recognized rules of civilized warfare. For example, the employment by a belligerent of a weapon the use of which is normally precluded by the law of war would constitute a lawful reprisal for intentional mistreatment of prisoners of war held by the enemy.
(c) Against Whom Permitted. Reprisals against the persons or property of prisoners of war, including the wounded and sick, and protected civilians are forbidden. Collective penalties and punishment of prisoners of war and protected civilians are likewise prohibited. However, reprisals may still be visited on enemy troops who have not yet fallen into the hands of the forces making the reprisals.
(d) When and how employed. Reprisals are never adopted merely for revenge, but only as an unavoidable last resort to induce the enemy to desist from unlawful practices. They should never be employed by individual soldiers except by direct orders of a commander, and the latter should give such orders only after careful inquiry into the alleged offense. The highest accessible military authority should be consulted unless immediate action is demanded, in which event a subordinate commander may order appropriate reprisals upon his own initiative. Ill-considered action may subsequently be found to have been wholly unjustified and will subject the responsible officer himself to punishment for a violation of the law of war. On the other hand, commanding officers must assume responsibility for retaliative measures when an unscrupulous enemy leaves no other recourse against the repetition of unlawful acts.
(f) Procedure. The rule requiring careful inquiry into the real occurrence will always be followed unless the safety of the troops requires immediate drastic action and the persons who actually committed the offence cannot be ascertained.
(g) Hostages. The taking of hostages is forbidden. The taking of prisoners by way of reprisal for acts previously committed (so-called “reprisal prisoners”) is likewise forbidden. 
United States, Field Manual 27-10, The Law of Land Warfare, US Department of the Army, 18 July 1956, as modified by Change No. 1, 15 July 1976, § 497(a), (d), (f) and (g).
United States of America
The US Air Force Pamphlet (1976) states:
In order to be considered as a reprisal, an act must have the following characteristics when employed:
(1) It must respond to grave and manifestly unlawful acts, committed by an adversary government, its military commanders, or combatants for whom the adversary is responsible.
(2) It must be for the purpose of compelling the adversary to observe the law of armed conflict. Reprisals cannot be undertaken for revenge, spite or punishment. Rather, they are directed against an adversary in order to induce him to refrain from further violations of the law of armed conflict. Thus, reprisals serve as an ultimate legal sanction or law enforcement mechanism. Above all, they are justifiable only to force an adversary to stop its extra-legal activity. If, for example, one party to an armed conflict commits a breach of law but follows that violation with an expression of regret and promise that it will not be repeated, and even takes steps to punish those immediately responsible, then any action taken by another party to “right” the situation cannot be justified as a lawful reprisal.
(3) There must be reasonable notice that reprisals will be taken. What degree of notice is required will depend upon the particular circumstances of each case. Notice is normally given after the violation but may, in appropriate circumstances, predate the violation. An example of notice is an appeal to the transgressor to cease its offending conduct and punish those responsible. Thus, such an appeal may serve both as a plea for compliance and a notice to the adversary that reprisals will be undertaken. 
United States, Air Force Pamphlet 110-31, International Law – The Conduct of Armed Conflict and Air Operations, US Department of the Air Force, 1976, § 10-7(c)(1), (2) and (3).
The Pamphlet also states:
If an act is a lawful reprisal, then as a legal measure it cannot lawfully be the excuse for a counter-reprisal. Under international law, as under domestic law, there can be no reprisal against a lawful reprisal. In fact, reprisals have frequently led to counter-reprisals, and the escalation of the conflicts through reprisals and counter-reprisals is one of the reasons for decline in the use of reprisals. 
United States, Air Force Pamphlet 110-31, International Law – The Conduct of Armed Conflict and Air Operations, US Department of the Air Force, 1976, § 10-7(a).
The Pamphlet further states:
[The reprisal] must be publicized. Since reprisals are undertaken to induce an adversary’s compliance with the recognized rules of armed conflict, any action taken as a reprisal must be announced as a reprisal and publicized so that the adversary is aware of its obligation to abide by the law. 
United States, Air Force Pamphlet 110-31, International Law – The Conduct of Armed Conflict and Air Operations, US Department of the Air Force, 1976, § 10-7(c)(7).
United States of America
The US Air Force Commander’s Handbook (1980) states:
A reprisal is an otherwise illegal act committed to persuade the enemy to cease some illegal activity on their part …
(1) While it is both lawful and proper to plan reprisal actions, as a practical matter, reprisals are often subject to abuse and merely result in escalation of the conflict.
(3) In most twentieth century conflicts, the United States has, as a matter of national policy, chosen not to carry out reprisals against the enemy, both because of the potential for escalation and because it is generally in our national interest to follow the law even if the enemy does not.
(4) The term “reprisal” is sometimes used to refer to any act of retaliation between the parties to a conflict. In law, however, the term should be limited to otherwise illegal acts done in reply to prior illegal acts of the enemy, as described in this paragraph. 
United States, Air Force Pamphlet 110-34, Commander’s Handbook on the Law of Armed Conflict, Judge Advocate General, US Department of the Air Force, 25 July 1980, § 8-4(b).
United States of America
The US Naval Handbook (1995) states:
A reprisal is an enforcement measure under the law of armed conflict consisting of an act which would otherwise be unlawful but which is justified as a response to the unlawful acts of an enemy. The sole purpose of a reprisal is to induce the enemy to cease its illegal activity and to comply with the law of armed conflict. 
United States, The Commander’s Handbook on the Law of Naval Operations, NWP 1-14M/MCWP 5-2.1/COMDTPUB P5800.7, issued by the Department of the Navy, Office of the Chief of Naval Operations and Headquarters, US Marine Corps, and Department of Transportation, US Coast Guard, October 1995 (formerly NWP 9 (Rev. A)/FMFM 1-10, October 1989), § 6.2.3.
The Handbook further states:
To be valid, a reprisal action must conform to the following criteria:
2. It must respond to illegal acts of warfare committed by an adversary government, its military commanders, or combatants for which the adversary is responsible. Anticipatory reprisal is not authorized.
4. Its purpose must be to cause the enemy to cease its unlawful activity. Therefore, acts taken in reprisal should be brought to the attention of the enemy in order to achieve maximum effectiveness. Reprisal must never be taken for revenge. 
United States, The Commander’s Handbook on the Law of Naval Operations, NWP 1-14M/MCWP 5-2.1/COMDTPUB P5800.7, issued by the Department of the Navy, Office of the Chief of Naval Operations and Headquarters, US Marine Corps, and Department of Transportation, US Coast Guard, October 1995 (formerly NWP 9 (Rev. A)/FMFM 1-10, October 1989), § 6.2.3.1.
The Handbook also provides:
Although reprisal is lawful when the foregoing requirements are met, there is always the risk that it will trigger retaliatory escalation (counter-reprisals) by the enemy. The United States has historically been reluctant to resort to reprisal for just this reason. 
United States, The Commander’s Handbook on the Law of Naval Operations, NWP 1-14M/MCWP 5-2.1/COMDTPUB P5800.7, issued by the Department of the Navy, Office of the Chief of Naval Operations and Headquarters, US Marine Corps, and Department of Transportation, US Coast Guard, October 1995 (formerly NWP 9 (Rev. A)/FMFM 1-10, October 1989), § 6.2.3.3.
United States of America
The Annotated Supplement to the US Naval Handbook (1997) states:
A careful inquiry by the injured belligerent into the alleged violating conduct should precede the authorization of any reprisal measure. This is subject to the important qualification that, in certain circumstances, an offended belligerent is justified in taking immediate reprisals against illegal acts of warfare, particularly in those situations where the safety of his armed forces would clearly be endangered by a continuance of the enemy’s illegal acts. 
United States, Annotated Supplement to the Commander’s Handbook on the Law of Naval Operations, prepared by the Oceans Law and Policy Department, Center for Naval Warfare Studies, Naval War College, Newport, Rhode Island, November 1997, § 6.2.3.1, footnote 38.
The Annotated Supplement also states:
Acts taken in reprisal may also be brought to the attention of neutrals if necessary to achieve maximum effectiveness. Since reprisals are undertaken to induce an adversary’s compliance with the recognized rules of armed conflict, any action taken as a reprisal must be announced as a reprisal and publicized so that the adversary is aware of its obligation to abide by the law and to ensure that the reprisal action is not, itself, viewed as an unlawful act. 
United States, Annotated Supplement to the Commander’s Handbook on the Law of Naval Operations, prepared by the Oceans Law and Policy Department, Center for Naval Warfare Studies, Naval War College, Newport, Rhode Island, November 1997, § 6.2.3.1, footnote 40.
The Annotated Supplement further states: “If an act is a lawful reprisal, it cannot lawfully be a basis for a counter-reprisal. Under international law, there can be no reprisal against a lawful reprisal.” 
United States, Annotated Supplement to the Commander’s Handbook on the Law of Naval Operations, prepared by the Oceans Law and Policy Department, Center for Naval Warfare Studies, Naval War College, Newport, Rhode Island, November 1997, § 6.2.3.1, footnote 43.
In another note, the Annotated Supplement states: “Although it is not prohibited to issue … an order [that no quarter will be given or that no prisoners will be taken] as a reprisal, this form of reprisal offers little military advantage.” 
United States, Annotated Supplement to the Commander’s Handbook on the Law of Naval Operations, prepared by the Oceans Law and Policy Department, Center for Naval Warfare Studies, Naval War College, Newport, Rhode Island, November 1997, § 11.7, footnote 45.
United States of America
The US Naval Handbook (2007) states:
If one nation violates the law, it may expect that others will reciprocate. Consequently, failure to comply with international law ordinarily involves greater political and economic costs than does observance. In short, nations comply with international law because it is in their interest to do so. 
United States, The Commander’s Handbook on the Law of Naval Operations, NWP 1-14M/MCWP 5-12.1/COMDTPUB P5800.7, issued by the Department of the Navy, Office of the Chief of Naval Operations and Headquarters, US Marine Corps, and Department of Homeland Security, US Coast Guard, July 2007, p. 20.
The Handbook also states:
6.2.4 Reprisal
A belligerent reprisal is an enforcement measure under the law of armed conflict consisting of an act that would otherwise be unlawful but which is justified as a response to the previous unlawful acts of an enemy. The sole purpose of a reprisal is to induce the enemy to cease its illegal activity and to comply with the law of armed conflict in the future. Reprisals may be taken against enemy armed forces, enemy civilians other than those in occupied territory, and enemy property.
6.2.4.1 Requirements for Reprisal
To be valid, a reprisal action must conform to the following criteria:
2. It must respond to illegal acts of warfare committed by an adversary government, its military commanders, or combatants for which the adversary is responsible. Anticipatory reprisal is not authorized.
4. Its purpose must be to cause the enemy to cease its unlawful activity. Therefore, acts taken in reprisal should be brought to the attention of the enemy in order to achieve maximum effectiveness. Reprisal must never be taken for revenge. 
United States, The Commander’s Handbook on the Law of Naval Operations, NWP 1-14M/MCWP 5-12.1/COMDTPUB P5800.7, issued by the Department of the Navy, Office of the Chief of Naval Operations and Headquarters, US Marine Corps, and Department of Homeland Security, US Coast Guard, July 2007, §§ 6.2.4 and 6.2.4.1.
Yugoslavia, Socialist Federal Republic of
The Socialist Federal Republic of Yugoslavia’s Military Manual (1988) states:
Reprisal, under the provisions of this military manual, means an act which is contrary to the laws of war, but whose unlawfulness is abolished because it is undertaken in response to acts of the enemy who does not respect the laws of war, in order to force him to stop such violations, and to respect the laws of war in future. 
Yugoslavia, Socialist Federal Republic of, Propisi o Primeri Pravila Medjunarodnog Ratnog Prava u Oruzanim Snagama SFRJ, PrU-2, Savezni Sekretarijat za Narodnu Odbranu (Pravna Uprava), 1988, § 27.
In another provision entitled “Aim and duration of reprisals”, the manual states: “The aim of reprisals is to prevent the enemy from repeating violations of the laws of war and to force him to respect the laws of war.” 
Yugoslavia, Socialist Federal Republic of, Propisi o Primeri Pravila Medjunarodnog Ratnog Prava u Oruzanim Snagama SFRJ, PrU-2, Savezni Sekretarijat za Narodnu Odbranu (Pravna Uprava), 1988, § 28.
The manual further provides: “The armed forces of the SFRY [Socialist Federal Republic of Yugoslavia] shall undertake reprisals against the enemy exceptionally and temporarily … Reprisals shall not be undertaken for every violation of the laws of war by the enemy but only in response to preceding, serious and repeated violations.” Moreover, it states: “The taking of hostages is prohibited in reprisal as well.” 
Yugoslavia, Socialist Federal Republic of, Propisi o Primeri Pravila Medjunarodnog Ratnog Prava u Oruzanim Snagama SFRJ, PrU-2, Savezni Sekretarijat za Narodnu Odbranu (Pravna Uprava), 1988, §§ 29 and 31.
Zimbabwe
Zimbabwe’s Code of Conduct for Combatants (1993) states: “Vengeance … [is] forbidden.” 
Zimbabwe, Code of Conduct for Combatants, Joint publication of the Zimbabwe Defence Forces and the International Committee of the Red Cross Regional Delegation in Harare, 1993, p. 11.
Democratic Republic of the Congo
Under the Democratic Republic of the Congo’s Code of Military Justice (1972), as amended in 1980, killing as a means of reprisal is prohibited. 
Democratic Republic of the Congo, Code of Military Justice, 1972, as amended in 1980, Article 523.
Italy
Italy’s Law of War Decree (1938), as amended in 1992, states: “Reprisals have the aim of inducing the enemy to observe the obligations deriving from international law and can be carried out either by means of acts similar to those committed [by the enemy] or by means of acts of a different nature.” 
Italy, Law of War Decree, 1938, as amended in 1992, Article 8.
Italy
Italy’s Wartime Military Penal Code (1941) provides for the punishment of a commander who orders the taking of acts of reprisal – other than those permitted under the law or international conventions – or who does not order them to be stopped. 
Italy, Wartime Military Penal Code, 1941, Article 176.
Luxembourg
Luxembourg’s Law on the Repression of War Crimes (1947) states that putting a person to death by means of reprisal is considered to be murder. 
Luxembourg, Law on the Repression of War Crimes, 1947, Article 2(3)
Niger
Niger’s Penal Code (1961), as amended in 2003, under a chapter entitled “Crimes against humanity and war crimes”, states: “No interest and no political, military or national necessity whatsoever can justify [war crimes under the 1949 Geneva Conventions and both the 1977 Additional Protocols I and II], not even as a means of reprisal.” 
Niger, Penal Code, 1961, as amended in 2003, Article 208.6.
Somalia
Somalia’s Military Criminal Code (1963) states: “A commander who orders hostile acts to be carried out by way of reprisals, except in cases where this is permitted by law or by international agreements … shall be punished by military confinement for 3 to 10 years. 
Somalia, Military Criminal Code, 1963, Article 360.
Spain
Under Spain’s Penal Code (1995) “anyone who … carries out or orders … reprisals or violent acts or threats in order to terrify [the civilian population]” is punishable. 
Spain, Penal Code, 1995, Article 611.
Italy
In the Priebke case in 1996, the Military Tribunal of Rome stated that reprisals “are to carry out an act in order to bring a violation to an end or to deter the commission of other violations [of international law]”. It went on to state that “a reprisal is based on the need to recognise the injured State a means of self-help allowing it to attack any interest of the offending State”. The Tribunal further stated:
It is useful to underline that a reprisal must have as its objective prevention or repression, but not revenge. It must aim for the cessation or non-repetition of an illegitimate injurious act, and must be carried out in a direct manner for this purpose and must not be more serious as the [initial] violation. Otherwise it becomes an act which is itself unjust and illegitimate, giving rise to an endless spiral of disproportionate reactions. 
Italy, Military Tribunal of Rome, Priebke case, Judgment in Trial of First Instance, 1 August 1996, Section 7.
Italy
In the Hass and Priebke case in 1997, the Military Tribunal of Rome made a similar statement to the one made in its judgment in the Priebke case in 1996 and added: “Reprisals basically are a sanction, that is a reaction to an unlawful act. The unlawfulness of the act to which it is replying gives lawfulness to the sanctional activities.” It further recalled the definition of reprisals contained in Italy’s Law of War Decree as amended. 
Italy, Military Tribunal of Rome, Hass and Priebke case, Judgment in Trial of First Instance, 22 July 1997, Section 4.
In its relevant parts, this judgment was confirmed by Italy’s Military Appeals Court and the Supreme Court of Cassation. 
Italy, Military Appeals Court, Hass and Priebke case, Judgment on Appeal, 7 March 1998; Supreme Court of Cassation, Hass and Priebke case, Judgment in Trial of Third Instance, 16 November 1998.
Netherlands
In its judgment in the Rauter case in 1948, the Special Court (War Criminals) at The Hague observed: “It is in fact generally accepted that a belligerent has the right to take reprisals as a requital for unlawful acts of war committed by the opponent.” Referring to the judgment of the US Military Tribunal at Nuremberg in the List case (The Hostages Trial) as well as to the conditions required for reprisals in general by the UK and US military regulations, the Court stated, however, that reprisals may never be taken for revenge but only as a means of inducing the enemy to desist from unlawful practices of warfare. 
Netherlands, Special Court (War Criminals) at The Hague, Rauter case, Judgment, 4 May 1948.
Nevertheless, on appeal, the Special Court of Cassation of the Netherlands stated:
In the proper sense one can speak of reprisals only when a State resorts, by means of its organs, to measures at variance with International Law, on account of the fact that its opponent – in this case the State with which it is at war – had begun, by means of one or more of its organs, to commit acts contrary to International Law, quite irrespective of the question as to what organ this may have been, Government or legislator, Commander of the Fleet, Commander of the Land Forces, or of the Air Force, diplomat or colonial governor. The measures which the appellant describes … as “reprisals” bear an entirely different character, they are indeed retaliatory measures taken in time of war by the occupant of enemy territory as a retaliation not of unlawful acts of the State with which it is at war, but of hostile acts of the population of the territory in question or of individual members thereof. 
Netherlands, Special Court of Cassation, Rauter case, Judgment, 12 January 1949.
Norway
In the Bruns case before the Norwegian Eidsivating Court of Appeal (sitting as the Tribunal of first instance) in 1946, the Counsel for Defence claimed that the Norwegian military organization and its activities were at variance with international law and that the Germans in fighting the organization were, therefore, justified in using methods contrary to international law. The German methods of carrying out interrogations had to be regarded as constituting reprisals. However, the Court held that the Norwegian underground military movement did not constitute a breach of international law and therefore the Germans were not justified in using torture against its members as a means of reprisal. 
Norway, Eidsivating Court of Appeal, Bruns case, Judgment, 20 March 1946.
In the same case, the Norwegian Supreme Court stated that it could not be established that the acts of torture had been carried out as reprisals. Reprisals were generally understood to aim at changing the adversary’s conduct and forcing him to keep to the generally accepted rules of lawful warfare. If this aim were to be achieved, the reprisals must be made public and announced as such. During the whole of the occupation there was no indication from the German side to the effect that their acts of torture were to be regarded as reprisals against the Norwegian military organization. They appeared to be German police measures designed to extort during interrogations information which could be used to punish people or could eventually have led to real reprisals to stop activities about which information was gained. The method applied to the interrogatories (“verschärfte Vernehmung”) was nothing but a German routine police method and could, therefore, not be regarded as a reprisal. 
Norway, Supreme Court, Bruns case, Judgment, 3 July 1946.
Norway
In the Flesch case in 1946 in which a German national was charged with having ordered the killing of Norwegian citizens who had allegedly been members of the Norwegian underground movement, the Frostating Court of Appeal stated that whatever the legal position, an act of reprisal can in no circumstances be pleaded in exculpation unless it was, at the time, announced publicly as such, or it appeared from the act itself that it was intended as a reprisal and showed clearly against what unlawful acts it was directed. None of the incidents in question fulfilled any of these minimum demands. As the defendant maintained that the acts were acts of reprisal directed against a number of subversive acts, the Frostating Court of Appeal did not regard the alleged acts of sabotage carried out by soldiers in uniform as constituting a breach of international law and therefore concluded that the acts committed by the accused could not be regarded as reprisals but must be considered as acts solely intended to terrorize the population in order to stem the underground movement. 
Norway, Frostating Court of Appeal, Flesch case, Judgment, 2 December 1946.
In the same case, the Norwegian Supreme Court agreed with the view held by the Frostating Court of Appeal to the effect that the execution of the Norwegian citizens without previous trial could not be regarded as constituting justifiable reprisals and made reference to what had been held by the Supreme Court in the Bruns case. 
Norway, Supreme Court, Flesch case, Decision, 12 February 1948.
United States of America
In the List case (The Hostages Trial) in the late 1947/48, the US Military Tribunal at Nuremberg held: “A reprisal is a response to an enemy’s violation of the laws of war which would otherwise be a violation on one’s own side.” 
United States, Military Tribunal at Nuremberg, List (The Hostages Trial) case, 8 July 1947–19 February 1948.
As to the difference between the taking of hostages and measures of reprisal, the Tribunal stated:
Where innocent individuals are seized and punished for a violation of the laws of war which has already occurred, no question of hostages is involved. It is nothing more than the infliction of a reprisal. Throughout the evidence in the present case, we find the term hostage applied where a reprisal only was involved.
However, it stated: “The term ‘reprisal prisoners’ will be considered as those individuals who are taken from the civilian population to be killed in retaliation for offences committed by unknown persons within the occupied area.” It also stated:
Where legality of action is absent, the shooting of innocent members of the population as a measure of reprisal is not only criminal but it has the effect of destroying the basic relationship between the occupant and the population. Such a condition can progressively degenerate into a reign of terror. Unlawful reprisals may bring on counter reprisals and create an endless cycle productive of chaos and crime. To prevent a distortion of the right into a barbarous method of repression, International Law provides a protective mantle against the abuse of the right. 
United States, Military Tribunal at Nuremberg, List (The Hostages Trial) case, 8 July 1947–19 February 1948.
Algeria
During the Algerian war of independence, the Front de Libération Nationale (FLN) denounced violations of IHL by French forces, stating: “It will be impossible for the FLN to respect the laws of war, if France persists in ignoring them.” 
El Moudjahid, Vol. 1, p. 372.
Argentina
During discussions on reprisals in Committee I of the CDDH, Argentina welcomed the efforts of the French delegation with regard to the introduction of a provision on the prohibition of reprisals in the 1977 Additional Protocol I. It further noted that the French proposal “should perhaps be completed so as to ensure that excessive reprisals did not lead to counter-reprisals”. 
Argentina, Statement at the CDDH, Official Records, Vol. IX, CDDH/I/SR.46, 28 April 1976, p. 61, §§ 32 and 35.
Australia
The Report on the Practice of Australia states: “Australia’s opinio juris is, with certain exceptions, supportive of a prohibition against belligerent reprisals.” 
Report on the Practice of Australia, 1998, Chapter 2.9.
Austria
During discussions on reprisals in Committee I of the CDDH, Austria stated that the French proposal on a prohibition of reprisals “gave a good definition of what a reprisal was”, stating, however, that Austria “had great difficulty with the idea of introducing into humanitarian law a legal sanction of the law of war always regarded as incompatible with the very principle of humanity”. 
Austria, Statement at the CDDH, Official Records, Vol. IX, CDDH/I/SR.47, 29 April 1976, p. 78, § 52.
Belarus
During discussions on reprisals in Committee I of the CDDH, Belarus, opposing the French proposal on a prohibition of reprisals and referring to a number of international instruments, stated that “there was a clearly expressed general trend towards the prohibition of reprisals”. It went on to say that “any toleration of the possibility of taking reprisals … would be in radical conflict with the spirit and meaning of the Geneva Conventions … Furthermore, it would run counter to a number of resolutions of the United Nations General Assembly.” 
Belarus, Statement at the CDDH, Official Records, Vol. IX, CDDH/I/SR.47, 29 April 1976, pp. 80 and 81, §§ 61 and 62.
Canada
In 1981, in a memorandum on Canada’s attitude to possible reservations with regard to the 1977 Additional Protocol I, the Canadian Ministry of Foreign Affairs noted that the 1977 Additional Protocol I “has so effectively limited the areas of permissible reprisals as to virtually constitute a total ban on them”. As a counter-argument against a reservation on reprisals, it noted, inter alia, that “reprisals are punitive rather than protective in character and therefore do not belong within the framework of a humanitarian agreement” and that “they cannot be controlled and contribute to counter-reprisals and a general escalation of violence”. 
Canada, Ministry of Foreign Affairs, Memorandum of the Legal Operations Division on the ratification of the 1977 Protocol I to the Geneva Red Cross Convention: Canada’s attitude to possible reservations, Doc. FLO-830, 16 June 1981, §§ 6 and 8.
The memorandum further stated:
A reservation on reprisals would also affect the operation of the general obligation contained in Article 1 of [the 1977 Additional Protocol I], viz, “The High Contracting Parties undertake to respect and ensure respect for this Protocol in all circumstances”. The phrase “in all circumstances” can be taken to include circumstances in which the adverse party is violating the Protocol. 
Canada, Ministry of Foreign Affairs, Memorandum of the Legal Operations Division on the ratification of the 1977 Protocol I to the Geneva Red Cross Convention: Canada’s attitude to possible reservations, Doc. FLO-830, 16 June 1981, § 12.
The memorandum also stated:
The “material breach” provision of the Vienna Convention on the Law of the Treaties (Article 60) cannot be invoked to permit a party to the Protocol to suspend the operation of the prohibition of reprisals in the face of e.g. enemy bombardment of the civilian population. The fifth paragraph of the Article 60 of the Convention … was expressly introduced in the Treaty to reinforce the already existing prohibitions against reprisals contained in the Geneva Conventions. It could therefore be argued that to enter a reservation on reprisals with respect to [the 1977 Additional Protocol I] defeats the object of the Conventions and Protocol and also the object of the relevant provision of the Vienna Convention. In other words, the reserving State would be attempting to do by reservation what it could not do by suspension of the agreement on the grounds of material breach. 
Canada, Ministry of Foreign Affairs, Memorandum of the Legal Operations Division on the ratification of the 1977 Protocol I to the Geneva Red Cross Convention: Canada’s attitude to possible reservations, Doc. FLO-830, 16 June 1981, § 13.
With regard to the compatibility of a possible reservation regarding reprisals in respect of the 1977 Additional Protocol I and Principle II of the Declaration on Principles Guiding Relations between Participating States of the Final Act of the CSCE Helsinki Summit of 1975, the memorandum noted: “The Final Act does not of course have the force of law except to the extent that it incorporates already binding obligations. Nevertheless, it comprises commitments undertaken at the highest political level on the part of the thirty-five states participating in the CSCE.” It therefore stated: “A reservation regarding reprisals under [the 1977 Additional Protocol I] is thus likely to provoke allegations of non-compliance with the CSCE Final Act.” 
Canada, Ministry of Foreign Affairs, Memorandum of the Legal Operations Division on the ratification of the 1977 Protocol I to the Geneva Red Cross Convention: Canada’s attitude to possible reservations, Doc. FLO-830, 16 June 1981, §§ 14–15.
Canada
In 1986, in an annex to a memorandum on Canada’s attitude to possible reservations with regard to the 1977 Additional Protocol I, the Canadian Ministry of Defence noted:
The expression “reprisal” is not defined in any international agreement. An acceptable definition would be as follows:
A reprisal is an otherwise illegal act of retaliation committed by one belligerent against another belligerent after that belligerent has violated the laws of war which is intended to cause that belligerent to comply in future with the laws of war. The act of reprisal must be proportional to the illegal act or acts committed by the other belligerent. 
Canada, Ministry of Defence, Memorandum on Ratification of the 1977 Additional Protocol I, Reprisals Reservation, Operational Considerations, Doc. 3440-13-2 (D Law/I), 14 March 1986, Annex A, § 1.
The Ministry of Defence further noted:
Under the [1949] Geneva Conventions, reprisals are permissible when directed against enemy military or civilian property or personnel behind the enemy’s lines. Under [the 1977 Additional Protocol I], the only legitimate reprisal targets are enemy armed forces or military objectives. Since these are already legitimate targets, the only means for carrying out reprisals would be the use of unlawful methods of combat, such as denial of quarter, or the use of unlawful weapons, such as biological weapons or lethal gases … The use of such methods or weapons would be more likely to increase the scale or intensity of the conflict than a response to a violation which is proportional and similar in kind. 
Canada, Ministry of Defence, Memorandum on Ratification of the 1977 Additional Protocol I, Reprisals Reservation, Operational Considerations, Doc. 3440-13-2 (D Law/I), 14 March 1986, Annex A, § 8.
The Ministry of Defence also stated: “It is difficult to point out individual cases where the possibility of reprisal deterred the commission of breaches of the law of armed conflict.”  
Canada, Ministry of Defence, Memorandum on Ratification of the 1977 Additional Protocol I, Reprisals Reservation, Operational Considerations, Doc. 3440-13-2 (D Law/I), 14 March 1986, Annex A, § 14.
Colombia
At the CDDH, following the adoption of Article 20 of the 1977 Additional Protocol I, Colombia stated that it “was opposed to any kind of reprisals and expressed regret that the term had not been adequately defined”. 
Colombia, Statement at the CDDH, Official Records, Vol. VI, CDDH/SR.37, 24 May 1977, § 34.
Czechoslovakia
During discussions on reprisals in Committee I of the CDDH, the representative of Czechoslovakia said that “his delegation was in favour of the absolute prohibition of all measures of reprisal”. 
Czechoslovakia, Statement at the CDDH, Official Records, Vol. IX, CDDH/I/SR.48, 30 April 1976, p. 94, § 52.
France
At the CDDH, France made a proposal for a draft article on reprisals within the 1977 Additional Protocol I – which it later withdrew – which read, inter alia, as follows:
Add a new Article 74 bis [to the 1977 Additional Protocol I]:
1. Reprisals shall be prohibited under the present Protocol.
2. Nevertheless, in the event of a belligerent State infringing the regulations laid down by the present Protocol and the State victim of that breach considering the violation to be so serious and deliberate as to render it imperative to call upon its perpetrator to respect the law, the prohibition referred to in paragraph 1 of the present Article may be waived on condition … 
France, Draft Article 74 bis Additional Protocol I submitted to the CDDH, Official Records, Vol. III, CDDH/I/ 221, 19 February 1975, p. 323.
France
At the CDDH, France made another proposal for a draft article on reprisals within the 1977 Additional Protocol I – which it later withdrew – which read, inter alia, as follows:
Add a new Article 74 bis [to the 1977 Additional Protocol I]:
1. In the event that the Party to a conflict commits serious, manifest and deliberate breaches of its obligations under this Protocol, and a Party victimized by these breaches considers it imperative to take action to compel the Party violating its obligations to cease doing so, the victimized Party shall be entitled, subject to the provisions of this Article, to resort to certain measures which are designed to repress the breaches and induce compliance with the Protocol, but which would otherwise be prohibited by the Protocol. 
France, Draft Article 74 bis Additional Protocol I submitted to the CDDH, Official Records, Vol. III, CDDH/I/ 221/Rev.1, 22 April 1976, p. 324.
France
During discussions in the First Committee of the CDDH with respect to its delegation’s draft provisions on reprisals in the 1977 Additional Protocol I, France noted that “many delegations had, in fact, felt that the effect of the proposal was to justify reprisals” but that “that was not the true aim of the proposal and in drafting it the French delegation had had in mind only the cause of humanitarian law”. 
France, Statement at the CDDH, Official Records, Vol. IX, CDDH/I/SR.46, 28 April 1976, p. 58, § 15.
France further noted:
The purpose of its proposal was not to allow the victim [of a breach of the law] to react with violence, but to give it the possibility under the Conventions of deterring the party committing the breach from continuing its action, of obliging it to respect the law. Such a threat … should of course arise from “serious, manifest and deliberate” breaches not requiring recourse to a commission of inquiry. They would clearly not just be the individual breaches mentioned in [draft] article 74. Such a possibility of deterrence sanctioned by a convention would have to be limited by strict conditions. 
France, Statement at the CDDH, Official Records, Vol. IX, CDDH/I/SR.46, 28 April 1976, p. 58, § 24.
France also noted: “Generally speaking, the French proposal was designed to cover cases in which, as the Oxford Manual stated, there was an urgent need to recall the party committing the breach to a respect for the rules to which it had subscribed.” 
France, Statement at the CDDH, Official Records, Vol. IX, CDDH/I/SR.46, 28 April 1976, p. 58, § 27.
Germany, Federal Republic of
In 1973, during a debate in the Sixth Committee of the UN General Assembly on the protection of human rights in times of armed conflict, the Federal Republic of Germany stated that “it supported proposals for a restriction on the right to resort to reprisals”. 
Germany, Federal Republic of, Statement before the Sixth Committee of the UN General Assembly, UN Doc. A/C.6/28/SR.1452, 3 December 1973, § 43.
German Democratic Republic
During discussions on reprisals in Committee I of the CDDH, the German Democratic Republic stated that his delegation felt that the French proposal on a prohibition of reprisals “would not help to implement [the 1977 Additional Protocol I] but would rather tend to weaken it; and he therefore strongly opposed it”. 
German Democratic Republic, Statement at the CDDH, Official Records, Vol. IX, CDDH/I/SR.47, 29 April 1976, p. 72, § 27.
Germany
The Report on the Practice of Germany states that the Rules of Engagement for the German Composite Force in Somalia provided that when it became necessary to open fire, “retaliation is forbidden”. 
Report on the Practice of Germany, 1997, Chapter 2.9, referring to Rules of Engagement for the German Composite Force in Somalia.
Hungary
During discussions on reprisals in Committee I of the CDDH, Hungary, opposing the French proposal on a prohibition of reprisals, stated:
If the parties to the conflict were evenly balanced, reprisals would lead to counter-reprisals and thus to escalation, rather than to respect for law. When the forces were not evenly balanced, reprisals would merely increase the advantage of the stronger power. 
Hungary, Statement at the CDDH, Official Records, Vol. IX, CDDH/I/SR.47, 29 April 1976, p. 79, § 56.
India
In its written statement submitted to the ICJ in the Nuclear Weapons case in 1995, India stated:
Reprisals or retaliation under international law are also governed by certain specific principles. First, reprisals to be valid and admissible could only be taken in response to a prior delict or wrongful act by a State … In other words, a nuclear weapon could not be used by way of reprisal against another State if that State did not commit any wrongful act or delict involving use of force. 
India, Written statement submitted to the ICJ, Nuclear Weapons case, 20 June 1995, p. 2.
After pointing out the principle of proportionality and the obligation to respect “certain fundamental principles of humanitarian law”, India stated:
In view of the above, use of nuclear weapons even by way of reprisal or retaliation, appears to be unlawful. In any case, if the wrongful use of force in the first instance did not involve the use of nuclear weapons, it is beyond doubt that even in response by way of retaliation States do not have the right to use nuclear weapons because of their special quality as weapons of mass destruction. 
India, Written statement submitted to the ICJ, Nuclear Weapons case, 20 June 1995, pp. 2–3.
Iraq
According to the Report on the Practice of Iraq, a reprisal is “a reaction from one party to the adverse party which undertook an act that led to damages thereto with the aim of revenge and deterrence”. 
Report on the Practice of Iraq, 1998, Chapter 2.9.
Islamic Republic of Iran
According to the Report on the Practice of the Islamic Republic of Iran, the opinio juris of the Islamic Republic of Iran is supportive of the right to take reprisals. It states that in practice during the Iran–Iraq War, the Islamic Republic of Iran resorted to reprisals. However, it also notes that in most cases, the Islamic Republic of Iran stopped carrying out reprisals after Iraq had ceased attacking civilian objects. 
Report on the Practice of the Islamic Republic of Iran, 1997, Chapter 2.9.
Italy
During discussions on reprisals in Committee I of the CDDH, the representative of Italy stated: that “from the standpoint of the required conditions laid down, he could accept the [French] proposal [on a prohibition of reprisals] in principle”. 
Italy, Statement at the CDDH, Official Records, Vol. IX, CDDH/I/SR.47, 29 April 1976, p. 77, § 48.
Mexico
At the CDDH, in an explanation of vote, Mexico stated:
The delegation of Mexico could not have accepted that a Protocol intended to strengthen the law concerning warlike activities should authorize reprisals, even if it were claimed that the intention was to force the enemy to respect humanitarian law … Experience shows that reprisals do not lead the enemy to respect humanitarian law, but result in an increase in violations and hostilities.
Legalization of reprisals, as proposed by France, would have enabled belligerents who were in breach of humanitarian law to claim every time that their breach was a legitimate reprisal sanctioned by international law. The delegation of Mexico believes that the mandatory nature of humanitarian law does not depend from the observance of its rules by the adverse Party, but stems from the inherently wrongful nature of the act prohibited by international humanitarian law. The Declaration on Principles of International Law concerning Friendly Relations and Co-operation among States in accordance with the Charter of the United Nations, unanimously adopted by the United Nations General Assembly in its resolution 2625 (XXV) of 24 October 1970, prohibits reprisals involving the use of force. The delegation of Mexico maintains that this Declaration is a valid interpretation of the United Nations Charter, so that the prohibition in question is legally binding. 
Mexico, Statement at the CDDH, Official Records, Vol. IX, CDDH/I/SR.73, 16 May 1977, pp. 449–450.
Netherlands
During discussions on reprisals in Committee I of the CDDH, the Netherlands stated that “reprisals were a very questionable means of securing respect for humanitarian law”. It further stated that “reprisals should remain a measure of last resort by which to induce an enemy to respect the law, provided that certain strict conditions and safeguards were observed”. 
Netherlands, Statement at the CDDH, Official Records, Vol. IX, CDDH/I/SR.48, 30 April 1976, p. 86, § 14.
Netherlands
In an explanatory memorandum submitted to the Dutch Parliament in the context of the ratification procedure of the Additional Protocols, the Government of the Netherlands stated: “A reprisal is a means of sanction, consisting in an act that itself is prohibited by international law, to which a State resorts in order to compel another State to cease a violation which that other State is committing.” It further stated:
In practice, it will often be very difficult to fulfil all the requirements that make a reprisal a justified action. Moreover, reprisals can lead to counter-reprisals and create a risk of a fast escalation of violations of humanitarian law. Finally, reprisals are objectionable because, even if all conditions are met, they create victims among persons who have no fault in the immediate causes of the reprisals. 
Netherlands, Lower House of Parliament, Explanatory memorandum for the ratification of the Additional Protocols, 1983–1984 Session, Doc. 18 277 (R 1247), No. 3, p. 40.
It also noted that under the 1977 Additional Protocol I, only the section on means and methods of warfare did not contain any prohibition on reprisals. Adopting an a contrario reasoning resulting from this, it took the view that reprisals could only be taken in the event of the use of prohibited weapons or of acts of perfidy. 
Netherlands, Lower House of Parliament, Explanatory memorandum for the ratification of the Additional Protocols, 1983–1984 Session, Doc. 18 277 (R 1247), No. 3, p. 41.
Norway
During discussions on reprisals in Committee I of the CDDH, Norway stated that “it was doubtful whether a victim State or party would be helped by resorting to actions directed against the innocent, even if it had done so in the past. Reprisals might well have the opposite effect, and lead to counter-reprisals.” 
Norway, Statement at the CDDH, Official Records, Vol. IX, CDDH/I/SR.47, 29 April 1976, p. 76, § 45.
Philippines
The Report on the Practice of the Philippines states: “Reprisals are generally prohibited.” 
Report on the Practice of the Philippines, 1997, Chapter 2.9.
Poland
During discussions on reprisals in Committee I of the CDDH, the representative of Poland noted:
To admit reprisals, even on a limited or exceptional scale, would be a backward step. All reprisals against persons and objects were prohibited by the Hague and Geneva Conventions, and … prohibition should be confirmed and extended by the Protocol. Moreover, reprisals would be contrary to the spirit of both the United Nations Charter and the Declaration on Principles of International Law concerning Friendly Relations and Co-operation among States (General Assembly Resolution 2625 (XXV)) … His delegation did not share the view of those who held that reprisals might help to ensure respect for international law. They could only lead to counter-reprisals, even if the strictest conditions were laid down … The Second World War had shown that it was completely possible to refrain from taking reprisals. 
Poland, Statement at the CDDH, Official Records, Vol. IX, CDDH/I/SR.46, 28 April 1976, p. 63, §§ 42 and 43.
Switzerland
During discussions on reprisals in Committee I of the CDDH, Switzerland stated that it supported the French amendment on a prohibition of reprisals “in principle”. 
Switzerland, Statement at the CDDH, Official Records, Vol. IX, CDDH/I/SR.46, 28 April 1976, p. 65, § 50.
Switzerland
In 1988, in a note on the prohibition on the use of chemical weapons, the Swiss Federal Department of Foreign Affairs stated: “The 1925 [Geneva Gas] Protocol declares a custom.” It added: “The 1925 [Geneva Gas] Protocol and custom prohibit the first use of chemical weapons and accept the lawfulness of second use only in the case of reprisals in kind.” 
Switzerland, Note of the Directorate for Public International Law of the Federal Department of Foreign Affairs, 15 December 1988, reprinted in Annuaire Suisse de Droit International, Vol. 46, 1989, pp. 244–247 (in French) and in Marco Sassóli and Antoine A. Bouvier, How Does Law Protect in War?, ICRC, Geneva, 1999, pp. 608–610 (in English).
Switzerland
Switzerland’s ABC of International Humanitarian Law (2009) states:
Reprisals
International humanitarian law does not include any general prohibition of reprisals. There are however numerous provisions that prohibit specific types of reprisal, in particular reprisals against Protected persons such as Civilians, the wounded and Prisoners of war. Also prohibited are reprisals against certain specific objects such as cultural property and places of worship, the natural environment, and installations that may cause a dangerous situation to occur (e.g. nuclear power stations and dams). 
Switzerland, Federal Department of Foreign Affairs, ABC of International Humanitarian Law, 2009, p. 37.
Union of Soviet Socialist Republics
During discussions on reprisals in Committee I of the CDDH, the representative of the USSR, opposing the French proposal on a prohibition of reprisals, stated that his delegation was “really concerned with reprisals, and analysis revealed that they contravened the meaning and spirit of the Geneva Conventions of 1949 and draft [Additional Protocol I]”. He also stated that the implementation of the French proposal “could in practice lead to far-reaching consequences and could even undermine the basis of international humanitarian law” and that “his delegation took the view that reprisals were inhumane and unjust. They inevitably involved persons who had not participated in the original violation alleged to have taken place, and they mainly affected the civilian population.” 
USSR, Statement at the CDDH, Official Records, Vol. IX, CDDH/I/SR.47, 29 April 1976, pp. 74 and 75, §§ 39 and 40.
United Kingdom of Great Britain and Northern Ireland
During discussions on reprisals in Committee I of the CDDH, the United Kingdom stated that it was “not true that at the present time [in 1976] the old system of lawful counter-measures was excluded; it still existed under customary law, and any exclusion must be expressed, as in the Geneva Conventions”. It also stated that it would “support the principle embodied in [the French proposal on a prohibition of reprisals]”. 
United Kingdom, Statement at the CDDH, Official Records, Vol. IX, CDDH/I/SR.47, 29 April 1976, p. 74, § 38.
United Kingdom of Great Britain and Northern Ireland
In its written statement submitted to the ICJ in the Nuclear Weapons case in 1995, the United Kingdom stated:
A belligerent reprisal is an action, taken by a party to an armed conflict, which would normally constitute a violation of the laws of armed conflict but which is lawful because it is taken in response to a prior violation of that law by an adversary … To be lawful, a belligerent reprisal must meet two conditions … It must meet the criteria for the regulation of reprisals, namely that it is taken in response to a prior wrong … [and] is undertaken for the purpose of putting an end to the enemy’s unlawful conduct and for preventing further illegalities. 
United Kingdom, Written statement submitted to the ICJ, Nuclear Weapons case, 16 June 1995, p. 58.
United Kingdom of Great Britain and Northern Ireland
Upon ratification of the 1977 Additional Protocol I, the United Kingdom stated that in the event of violations of Articles 51–55 of the 1977 Additional Protocol I by the adversary, the United Kingdom would regard itself entitled to take measures otherwise prohibited by these Articles, noting, however, that this would be true “to the extent that it considers such measures necessary for the sole purpose of compelling the adverse party to cease committing violations under those Articles”. 
United Kingdom, Reservations and declarations made upon ratification of the 1977 Additional Protocol I, 28 January 1998, § (m).
United States of America
In 1980, in a footnote to a memorandum of law on the “Reported Use of Chemical Agents in Afghanistan, Laos, and Kampuchea”, a legal adviser of the US Department of State noted that “reprisals are permitted under the laws of war only for the limited purpose of compelling the other belligerent to observe the laws of war”. 
United States, Department of State, Memorandum of law by a Legal Adviser on the “Reported Use of Chemical Agents in Afghanistan, Laos, and Kampuchea”, 9 April 1980, reprinted in Marian Nash Leich, Digest of United States Practice in International Law, 1980, Department of State Publication 9610, Washington, D.C., December 1986, pp. 1034 and 1041, footnote 38.
United States of America
In 1987, a Legal Adviser of the US Department of State, explaining “the position of the United States on current law of war agreements”, stated with regard to Article 51 of the 1977 Additional Protocol I: “[This provision] prohibits any reprisal attacks against the civilian population, that is, attacks that would otherwise be forbidden but that are in response to the enemy’s own violations of the law and are intended to deter future violations.” 
United States, Remarks of Judge Abraham D. Sofaer, Legal Adviser, US Department of State, The Sixth Annual American Red Cross-Washington College of Law Conference on International Humanitarian Law: A Workshop on Customary International Law and the 1977 Protocols Additional to the 1949 Geneva Conventions, 22 January 1987, American University Journal of International Law and Policy, Vol. 2, 1987, p. 469.
United States of America
In its written statement submitted to the ICJ in the Nuclear Weapons case in 1995, the United States stated:
For the purpose of the law of armed conflict, reprisals are lawful acts of retaliation in the form of conduct that would otherwise be unlawful, resorted to by one belligerent in response to violations of the law of war by another belligerent. Such reprisals would be lawful if conducted in accordance with the applicable principles governing belligerent reprisals. Specifically, the reprisals must be taken with the intent to cause the enemy to cease violations of the law of armed conflict … As in the case of other requirements of the law of armed conflict, a judgment about compliance of any use of nuclear weapons with these requirements would have to be made on the basis of the actual circumstances in each case, and could not be made in advance or in the abstract. 
United States, Written statement submitted to the ICJ, Nuclear Weapons case, 20 June 1995, p. 30.
Venezuela
During discussions on reprisals in Committee I of the CDDH, the representative of Venezuela stated that the French proposal on a prohibition of reprisals “was excellent”. However, he suggested that the final text “should also include a formal prohibition of counter-reprisals so as to avoid situations in which the parties to a conflict become involved in a vicious circle and also because counter-reprisals were a negation of the law”. 
Venezuela, Statement at the CDDH, Official Records, Vol. IX, CDDH/I/SR.47, 29 April 1976, p. 72, §§ 30 and 32.
Yugoslavia, Socialist Federal Republic of
In 1991, notwithstanding the 1991 Memorandum of Understanding on the Application of IHL between Croatia and the Socialist Federal Republic of Yugoslavia, according to which these States agreed that hostilities should be conducted in accordance with, inter alia, Articles 48–58 of the 1977 Additional Protocol I, the Yugoslav People’s Army (YPA) issued a general warning to the attention of the Croatian authorities to the effect that “a number of impudent crimes has been committed against the members of the Y.P.A. … Family members of the Y.P.A. are being maltreated, persecuted and destroyed in many different ways. This cannot be tolerated any longer.” The YPA therefore warned:
1. For every attacked and seized object of the [YPA] – an object of vital importance for the Republic of Croatia will be destroyed immediately.
2. For every attacked and occupied garrison – an object of vital importance to the town in which the garrison is located will be destroyed. This is, at the same time, a warning to civilian persons to abandon such settlement in time. 
Yugoslavia, Socialist Federal Republic of, Headquarters of the Supreme Command of the Armed Forces of the S.F.R.Y, Warning to the attention of the President of Croatia, the Government of Croatia and the General Staff of the Croatian Army, 1 October 1991.
According to the Report on the Practice of the Federal Republic of Yugoslavia, “this warning calls for detailed analysis, but arguably it can be classified as a threat of the use of belligerent reprisals”. 
Report on the Practice of the Federal Republic of Yugoslavia, 1997, Chapter 2.9.
UN General Assembly
In 2001, the UN General Assembly adopted a resolution on the responsibility of States for internationally wrongful acts, to which the 2001 ILC Draft Articles on State Responsibility, and thus Article 49 entitled “Object and limits of countermeasures”, were annexed. In the resolution, the General Assembly took note of the Draft Articles and commended them to the attention of governments “without prejudice to the question of their future adoption or other appropriate action”. 
UN General Assembly, Res. 56/83, 12 December 2001, § 3 and Annex, adopted without a vote.
UN Commission of Experts Established pursuant to Security Council Resolution 780 (1992)
In 1994, in its final report on grave breaches of the Geneva Conventions and other violations of IHL committed in the former Yugoslavia, the UN Commission of Experts Established pursuant to Security Council Resolution 780 (1992) stated:
63. A reprisal must be distinguished from a simple act of retaliation or vengeance. An unlawful act committed under the guise of retaliation or vengeance remains unlawful, and the claim of retaliation or vengeance is no defence.
64. A reprisal is an otherwise illegal act resorted to after the adverse party has himself indulged in illegal acts and refused to desist therefrom after being called upon to do so. The purpose of a reprisal is to compel the adverse party to terminate its illegal activity. 
UN Commission of Experts Established pursuant to Security Council Resolution 780 (1992), Final report, UN Doc. S/1994/674, 27 May 1994, §§ 63–64.
No data.
CSCE Helsinki Summit (1975)
The Declaration on Principles Guiding Relations between Participating States of the Final Act of the CSCE Helsinki Summit of Heads of State or Government in 1975 provides that the participating States “will also refrain in their mutual relations from any act of reprisal by force”. 
CSCE, Final Act of the 1975 Summit, Declaration on Principles Guiding Relations between Participating States, Helsinki, 1 August 1975, Principle II.
International Court of Justice
In its advisory opinion in the Namibia case in 1971, the ICJ considered it to be a general principle of law that “a right of termination on account of breach must be presumed to exist in respect of all treaties, except as regards provisions relating to the protection of the human person contained in treaties of a humanitarian character”. 
ICJ, Namibia case, Advisory Opinion, 21 June 1971, § 96.
Special Arbitral Tribunal
In the Naulilaa case in 1928 regarding acts taken by Germany against Portugal in reprisal for the killing of three German officials by Portuguese soldiers, the Special Arbitral Tribunal stated:
The latest doctrine, and more particularly German doctrine, defines reprisals in these terms:
Reprisals are an act of taking the law into its own hands … by the injured State, an act carried out – after an unfulfilled demand – in response to an act contrary to the law of nations by the offending State. Their effect is to suspend temporarily, in the relations between the two States, the observance of a particular rule of the law of nations. They are limited by the experiences of mankind and the rules of good faith, applicable in relations between States. They would be illegal if an earlier act, contrary to the law of nations, had not furnished the motive. 
Special Arbitral Tribunal, Naulilaa case, Decision, 31 July 1928, pp. 1025–1026.
Special Arbitral Tribunal
In the Cysne case in 1930 dealing with the destruction of a Portuguese vessel by Germany in reprisal for violations of international law by the United Kingdom, the Special Arbitral Tribunal stated:
As the respondent maintains, an act contrary to international law may be justified, by way of reprisals, if motivated by a like act … However, the German argument, which is sound up to this point, overlooks an essential question which can be put in the following terms: Could the measure which the German Government was entitled to take, by way of reprisals against Great Britain and its allies, be applied to neutral vessels and specifically to Portuguese vessels?
The answer must be in the negative, even according to the opinion of German scholars. This answer is the logical consequence of the rule that reprisals, which constitute an act in principle contrary to the law of nations, are defensible only in so far as they were provoked by some other act likewise contrary to that law. Only reprisals taken against the provoking State are permissible. Admittedly, it can happen that legitimate reprisals taken against an offending State may affect the nationals of an innocent State. But that would be an indirect and unintentional consequence which, in practice, the injured State will always endeavor to avoid or to limit as far as possible. By contrast, the measures taken by the German State in 1915 against neutral merchant vessels were aimed directly and deliberately against the nationals of States innocent of the violations of the London Declaration attributed to Great Britain and its allies. Consequently, not being in conformity with the Declaration, they constituted acts contrary to the law of nations, unless one of the neutral States had committed against Germany an act contrary to the law of nations that could make it liable to reprisals. There is no evidence of any such act having been committed by Portugal, and the German claim relies exclusively on the acts committed by Great Britain and its allies. Hence, in the absence of any Portuguese provocation warranting reprisals, the German State must be held not to have been entitled to violate article 23 of the Declaration in respect of Portuguese nationals. Accordingly, it was contrary to the law of nations to treat the cargo of the Cysne as absolute contraband.  
Special Arbitral Tribunal, Cysne case, Decision, 30 June 1930, pp. 1956–1057.
No data.
American Law Institute
The Restatement (Third) of the Foreign Relations Law of the United States, adopted and promulgated by the American Law Institute in 1986, provides:
(1) Subject to Subsection (2), a state victim of a violation of an international obligation by another state may resort to countermeasures that might otherwise be unlawful, if such measures
(a) are necessary to terminate the violation or prevent further violation, or to remedy the violation; and
(b) are not out of proportion to the violation and the injury suffered.
(2) The threat or use of force in response to a violation of international law is subject to prohibitions on the threat or use of force in the United Nations Charter, as well as to Subsection (1). 
The American Law Institute, Restatement Third. Restatement of the Foreign Relations Law of the United States, American Law Institute Publishers, St. Paul, 1987, § 905.
Greenwood
Greenwood states:
It has never been doubted that reprisals may only be taken in response to a violation of international law by the party against which they are directed (or its ally). In the case of belligerent reprisals, however, a question arises about the nature of the prior violation which provides the justification for the reprisal. Belligerent reprisals consist of acts which, if they could not be justified as reprisals, would constitute violations of the law which regulates the conduct of war or armed conflict … The better view is … that belligerent reprisals may lawfully be taken only in response to a prior violation of the law of armed conflict and not in retaliation for an unlawful resort to force.
The prior violation to which the reprisals are a response must be imputable to the State against which the reprisals are directed, or perhaps to an ally of that State … Allies of a State which is responsible for a violation of the laws of armed conflict may also be subjected to reprisals where they are themselves implicated in the violation and probably even where they have no direct involvement if the violation takes the form of a policy of conducting hostilities in a particular way. Thus, the United Kingdom extended the maritime reprisals adopted against Germany to Italy and Japan when they entered the Second World War. The United Kingdom maintained that, in allying themselves with Germany, Italy and Japan had made themselves “party to the methods of waging war adopted by Germany” and would “share in any advantages derived therefrom”. 
Christopher Greenwood, “The Twilight of the Law of Belligerent Reprisals”, Netherlands Yearbook of International Law, Vol. 20, 1989, pp. 40–43. On the extension by the United Kingdom of maritime reprisals adopted against Germany to Italy; see also Frits Kalshoven, Belligerent Reprisals, A. W. Sijthof, Leyden, 1971, pp. 120 and 156.