Practice Relating to Rule 43. Application of General Principles on the Conduct of Hostilities to the Natural Environment

Note: For practice concerning the general rules on the conduct of hostilities, see Rules 1–24. For practice concerning the destruction of property, see Rules 50–51. For practice concerning attacks on forests or other kinds of plant cover by incendiary weapons, see Rule 84 and by herbicides, see Rule 76.
Additional Protocol I
Article 55 of the 1977 Additional Protocol I provides:
1. Care shall be taken in warfare to protect the natural environment against widespread, long-term and severe damage.
2. Attacks against the natural environment by way of reprisals are prohibited. 
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 55. Article 55 was adopted by consensus. CDDH, Official Records, Vol. VI, CDDH/SR.42, 27 May 1977, p. 209.
Protocol III to the Convention on Certain Conventional Weapons
Article 2(4) of the 1980 Protocol III to the Convention on Certain Conventional Weapons states:
It is prohibited to make forests or other kinds of plant cover the object of attack by incendiary weapons except when such natural elements are used to cover, conceal or camouflage combatants or other military objectives, or are themselves military objectives. 
Protocol on Prohibitions or Restrictions on the Use of Incendiary Weapons, to the Convention on Prohibitions or Restrictions on the use of Certain Conventional Weapons which May Be Deemed to Be Excessively Injurious or to Have Indiscriminate Effects, Geneva, 10 October 1980, Article 2(4).
ICC Statute
Pursuant to Article 8(2)(b)(iv) of the 1998 ICC Statute, “[i]ntentionally launching an attack in the knowledge that such attack will cause … widespread, long-term and severe damage to the natural environment which would be clearly excessive in relation to the concrete and direct overall military advantage anticipated” constitutes a war crime in international armed conflicts. 
Statute of the International Criminal Court, adopted by the UN Diplomatic Conference of Plenipotentiaries on the Establishment of an International Criminal Court, Rome, 17 July 1998, UN Doc. A/CONF.183/9, Article 8(2)(b)(iv).
Rio Declaration
Paragraph 39.6 of the 1992 Rio Declaration provides:
Measures in accordance with international law should be considered to address, in times of armed conflict, large-scale destruction of the environment that cannot be justified under international law. The General Assembly and its Sixth Committee are the appropriate forums to deal with this subject. The specific competence and role of the International Committee of the Red Cross should be taken into account. 
Rio Declaration on Environment and Development, adopted at the United Nations Conference on Environment and Development, Rio de Janeiro, 13 June 1992, UN Doc. A/CONF.151/26 (Vol. I), 12 August 1992, endorsed by the UN General Assembly, Res. 47/190, 22 December 1992; see also Res. 47/191, 22 December 1992 and Res. 49/113, 19 December 1994, para. 39.6.
Guidelines on the Protection of the Environment in Times of Armed Conflict
The 1994 Guidelines on the Protection of the Environment in Times of Armed Conflict provides:
(4) In addition to the specific rules set out below, the general principles of international law applicable in armed conflict – such as the principle of distinction and the principle of proportionality – provide protection to the environment. In particular, only military objectives may be attacked and no methods or means of warfare which cause excessive damage shall be employed. Precautions shall be taken in military operations as required by international law.
(6) Parties to a non-international armed conflict are encouraged to apply the same rules that provide protection to the environment in international armed conflict and, accordingly, States are urged to incorporate such rules in their military manuals and instructions on the laws of war in a way that does not discriminate on the basis of how the conflict is characterized.
(8) Destruction of the environment not justified by military necessity violates international humanitarian law. Under certain circumstances, such destruction is punishable as a grave breach of international humanitarian law.
(9) The general prohibition on destroying civilian objects, unless such destruction is justified by military necessity, also protects the environment. 
Revised Guidelines for Military Manuals and Instructions on the Protection of the Environment in Times of Armed Conflict, prepared by the International Committee of the Red Cross and presented to the UN Secretary-General, annexed to Report of the Secretary-General on the United Nations Decade of International Law, UN Doc. A/49/323, 19 August 1994, pp. 49–53, §§ 4, 6, 8 and 9.
San Remo Manual
Paragraph 13(c) of the 1994 San Remo Manual defines as “collateral casualties” or “collateral damage”, inter alia, “damage to or the destruction of the natural environment”. 
Louise Doswald-Beck (ed.), San Remo Manual on International Law Applicable to Armed Conflicts at Sea, 12 June 1994, Prepared by international lawyers and naval experts convened by the International Institute of Humanitarian Law, Cambridge University Press, Cambridge, 1995, § 13(c).
San Remo Manual
Paragraph 44 of the 1994 San Remo Manual provides:
Methods and means of warfare should be employed with due regard for the natural environment taking into account the relevant rules of international law. Damage to or destruction of the natural environment not justified by military necessity and carried out wantonly is prohibited. 
Louise Doswald-Beck (ed.), San Remo Manual on International Law Applicable to Armed Conflicts at Sea, 12 June 1994, Prepared by international lawyers and naval experts convened by the International Institute of Humanitarian Law, Cambridge University Press, Cambridge, 1995, § 44.
UNTAET Regulation No. 2000/15
The UNTAET Regulation No. 2000/15 establishes panels with exclusive jurisdiction over serious criminal offences, including war crimes. According to Section 6(1)(b)(iv), “[i]ntentionally launching an attack in the knowledge that such attack will cause … widespread, long-term and severe damage to the natural environment which would be clearly excessive in relation to the concrete and direct overall military advantage anticipated” constitutes a war crime in international armed conflicts. 
Regulation on the Establishment of Panels with Exclusive Jurisdiction over Serious Criminal Offences, UN Doc. UNTAET/REG/2000/15, Dili, 6 June 2000, Section 6(1)(b)(iv).
Australia
Australia’s Defence Force Manual (1994) states:
The natural environment is not a legitimate object of attack. Destruction of the environment, not justified by military necessity, is punishable as a violation of international law … The general prohibition on destroying civilian objects, unless justified by military necessity, also protects the environment. 
Australia, Manual on Law of Armed Conflict, Australian Defence Force Publication, Operations Series, ADFP 37 – Interim Edition, 1994, § 545(a) and (c).
Australia
Australia’s LOAC Manual (2006) states:
The natural environment is not a legitimate object of attack. Destruction of the environment, not justified by military necessity, is punishable as a violation of international law … The general prohibition on destroying civilian objects, unless justified by military necessity, also protects the environment … In the event of breaches to the rules protecting the environment, commanders are required to stop the violations, take action to prevent further breaches and report violations to higher authority so further action can be taken. 
Australia, The Manual of the Law of Armed Conflict, Australian Defence Doctrine Publication 06.4, Australian Defence Headquarters, 11 May 2006, § 5.50.
The LOAC Manual (2006) replaces both the Defence Force Manual (1994) and the Commanders’ Guide (1994).
Belgium
According to Belgium’s Regulations on the Tactical Use of Large Units (1994), restrictions on the use of weapons can result from “the obligation to respect the rules of the laws of war relative to the conduct of hostilities. These rules concern, inter alia, the choice of means and methods of warfare, the protection of the civilian population, civilian objects and the environment.” 
Belgium, L’Emploi Tactique des Grandes Unités, Règlement G 119, Ministère de la Défense Nationale, Etat-Major Général, Force Terrestre, Sections Operations et Entraînement, 1994 (édition provisoire), Article 208(c)(2).
Burundi
Burundi’s Regulations on International Humanitarian Law (2007) lists “the natural environment” under “civilian objects”. 
Burundi, Règlement n° 98 sur le droit international humanitaire, Ministère de la Défense Nationale et des Anciens Combattants, Projet “Moralisation” (BDI/B-05), August 2007, Part I bis, p. 5.
The Regulations adds: “Civilian objects may not be attacked. … This protection is directed at … the natural environment …”. 
Burundi, Règlement n° 98 sur le droit international humanitaire, Ministère de la Défense Nationale et des Anciens Combattants, Projet “Moralisation” (BDI/B-05), August 2007, Part I bis, p. 5; see also Part I bis, p. 19.
Chad
Chad’s Instructor’s Manual (2006) includes the “natural environment” amongst objects that have special protection. It adds that “[such] protection applies in all circumstances. Immunity may only be waived in exceptional cases.” 
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. 16.
Côte d’Ivoire
Côte d’Ivoire’s Teaching Manual (2007) provides in Book III, Volume 1 (Instruction of first-year trainee officers):
IV.1. Natural environment
As a starting point, let us consider the basic principles of the law of armed conflicts with regard to operations which could have an impact on the natural environment. Are the means and methods to be employed justified, or is there a risk that they cause superfluous damage to the environment? Is the incidental ecological damage caused excessive in relation to the concrete and direct military advantage anticipated? 
Côte d’Ivoire, Droit de la guerre, Manuel d’instruction, Livre III, Tome 1: Instruction de l’élève officier d’active de 1ère année, Manuel de l’élève, Ministère de la Défense, Forces Armées Nationales, November 2007, p. 35; see also 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, p. 32.
Italy
Italy’s IHL Manual (1991) defines “attacks against the natural environment” as a war crime. 
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, § 85.
Mexico
Mexico’s Army and Air Force Manual (2009), in a section on the 1977 Additional Protocol I, states that “attacks on the environment are prohibited”. 
Mexico, Manual de Derecho Internacional Humanitario para el Ejército y la Fuerza Área Mexicanos, Ministry of National Defence, June 2009, § 255.
In the same section, the manual also states that “attacks on the natural environment are specifically prohibited.” 
Mexico, Manual de Derecho Internacional Humanitario para el Ejército y la Fuerza Área Mexicanos, Ministry of National Defence, June 2009, § 260.
Netherlands
The Military Manual (2005) of the Netherlands states: “It is also forbidden to use methods or means which cause extensive, long-lasting and serious damage to the natural environment, or which may be expected to cause such damage.” 
Netherlands, Humanitair Oorlogsrecht: Handleiding, Voorschift No. 27-412, Koninklijke Landmacht, Militair Juridische Dienst, 2005, § 0404; see also § 0405.
In its chapter on non-international armed conflict, the manual states:
The natural environment
Areas (of land or sea) may be attacked only if they are a military objective and may be occupied or used for military purposes only if a military need for this exists. Where this occurs, or other military objectives are attacked, damage to the natural environment must be limited. 
Netherlands, Humanitair Oorlogsrecht: Handleiding, Voorschift No. 27-412, Koninklijke Landmacht, Militair Juridische Dienst, 2005, § 1037.
Switzerland
Switzerland’s Regulation on Legal Bases for Conduct during an Engagement (2005) states:
14 Protected objects
14.5 Natural environment
217 Care shall be taken in warfare to protect the natural environment against widespread, long-term and severe damage.
218 Methods and means of warfare that are intended or may be expected to cause such damage to the environment are prohibited.
15 Methods of warfare
15.2 Prohibited methods of warfare
225 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.
17 Sanctions for violations of the international law of armed conflict
17.1 General provisions
237 The following in particular are criminal offences: … harmful acts against internationally protected persons and objects[.] 
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, §§ 217–218, 225 and 237.
United Kingdom of Great Britain and Northern Ireland
The UK LOAC Manual (2004) states:
Methods and means of warfare should be employed with due regard for the natural environment, taking into account the relevant rules of international law. Damage to or destruction of the natural environment not justified by military necessity and carried out wantonly is prohibited. 
United Kingdom, The Manual of the Law of Armed Conflict, Ministry of Defence, 1 July 2004, § 12.24.
In the conduct of attacks against targets on land, the manual states that “[t]he natural environment is specially protected”. 
United Kingdom, The Manual of the Law of Armed Conflict, Ministry of Defence, 1 July 2004, § 12.26.
In its chapter on maritime warfare, the manual provides:
Methods and means of warfare should be employed with due regard for the natural environment taking into account the relevant rules of international law. Damage to or destruction of the natural environment not justified by military necessity is prohibited. 
United Kingdom, The Manual of the Law of Armed Conflict, Ministry of Defence, 1 July 2004, § 13.30.
United States of America
The US Naval Handbook (1995) provides: “The commander has an affirmative obligation to avoid unnecessary damage to the environment.”  
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), § 8.1.3.
United States of America
The US Naval Handbook (2007) states:
Destruction of the natural environment not necessitated by mission accomplishment and carried out wantonly is prohibited. Therefore, a commander should consider the environmental damage that will result from an attack on a legitimate military objective as one of the factors during targeting analysis. 
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, § 8.4.
Australia
Australia’s ICC (Consequential Amendments) Act (2002) incorporates in the Criminal Code the war crimes defined in the 1998 ICC Statute, including launching an attack in the knowledge that such attack will cause “widespread, long-term and severe damage to the natural environment … of such an extent as to be excessive in relation to the concrete and direct military advantage anticipated” in international armed conflicts. 
Australia, ICC (Consequential Amendments) Act, 2002, Schedule 1, § 268.38(2).
Belgium
Belgium’s Penal Code (1867), as amended in 2003, provides:
War crimes envisaged in the 1949 [Geneva] Conventions … and in the [1977 Additional Protocols I and II] … , as well as in Article 8(2)(f) of the [1998 ICC Statute], and listed below, … constitute crimes under international law and shall be punished in accordance with the provisions of the present title … :
22. intentionally launching an attack in the knowledge that such attack will cause … widespread, long-term and severe damage to the natural environment, which would be excessive in relation to the concrete and direct military advantage anticipated. 
Belgium, Penal Code, 1867, as amended on 5 August 2003, Chapter III, Title I bis, Article 136 quater, § 1(22).
Belgium
Belgium’s Law relating to the Repression of Grave Breaches of International Humanitarian Law (1993), as amended in 2003, provides:
War crimes envisaged in the 1949 [Geneva] Conventions … and in the [1977 Additional Protocols I and II] … , as well as in Article 8(2)(f) of the [1998 ICC Statute], and listed below, … constitute crimes under international law and shall be punished in accordance with the provisions of the present title … :
12. intentionally launching an attack in the knowledge that such attack will cause … widespread, long-term and severe damage to the natural environment, which would be excessive in relation to the concrete and direct military advantage anticipated. 
Belgium, Law relating to the Repression of Grave Breaches of International Humanitarian Law, 1993, as amended on 23 April 2003, Article 1 ter, § 1(12).
Burundi
Burundi’s Law on Genocide, Crimes against Humanity and War Crimes (2003) states:
[The following are] considered as war crimes:
B. Other serious violations of the laws and customs applicable in international armed conflicts, within the established framework of international law, namely, any of the following acts:
d) launching a deliberate attack in the knowledge that such attack will cause … widespread, long-term and severe damage to the natural environment which would be clearly excessive in relation to the concrete and direct overall military advantage anticipated. 
Burundi, Law on Genocide, Crimes against Humanity and War Crimes, 2003, Article 4(B)(d).
Burundi
Burundi’s Penal Code (2009) states:
“War crimes” means crimes which are committed as part of a plan or policy or as part of a large-scale commission of such crimes, in particular:
2. … [S]erious violations of the laws and customs applicable in international armed conflict, within the established framework of international law, namely, any of the following acts:
4°. Intentionally launching an attack in the knowledge that such attack will cause incidental, … widespread, long-term and severe damage to the natural environment which would be clearly excessive in relation to the concrete and direct overall military advantage anticipated. 
Burundi, Penal Code, 2009, Article 198(2)(4°).
Canada
Canada’s Crimes against Humanity and War Crimes Act (2000) provides that the war crimes defined in Article 8(2) of the 1998 ICC Statute are “crimes according to customary international law” and, as such, indictable offences under the Act. 
Canada, Crimes against Humanity and War Crimes Act, 2000, Section 4(1) and (4).
Congo
The Congo’s Genocide, War Crimes and Crimes against Humanity Act (1998) defines war crimes with reference to the categories of crimes set out in Article 8 of the 1998 ICC Statute. 
Congo, Genocide, War Crimes and Crimes against Humanity Act, 1998, Article 4.
Czech Republic
The Czech Republic’s Criminal Code (1961), as amended in 1999, in a part entitled “Crimes against humanity”, provides for the punishment of “a commander who, contrary to the provisions of international law on means and methods of warfare, intentionally: … (d) destroys or damages … a place internationally-recognized with regard to the protection of nature”. 
Czech Republic, Criminal Code, 1961, as amended in 1999, Article 262(2)(d).
Democratic Republic of the Congo
The Democratic Republic of the Congo’s Military Penal Code (2002) provides:
Any of the following acts, perpetrated as part of a widespread or systematic attack knowingly directed against the Republic or the civilian population, equally constitutes a crime against humanity and is punished by death, whether committed in time of peace or in time of war:
9. Grave devastation of the fauna, of the flora, of surface or underground resources;
10. Destruction of the universal natural or cultural heritage. 
Democratic Republic of the Congo, Military Penal Code, 2002, Article 169.
Denmark
Denmark’s Military Criminal Code (1973), as amended in 1978, provides:
Any person who uses war instruments or procedures the application of which violates an international agreement entered into by Denmark or the general rules of international law, shall be liable to the same penalty [i.e. a fine, lenient imprisonment or up to 12 years’ imprisonment]. 
Denmark, Military Criminal Code, 1973, as amended in 1978, § 25(1).
Denmark’s Military Criminal Code (2005) provides:
Any person who deliberately uses war means [“krigsmiddel”] or procedures the application of which violates an international agreement entered into by Denmark or international customary law, shall be liable to the same penalty [i.e. imprisonment up to life imprisonment]. 
Denmark, Military Criminal Code, 2005, § 36(2).
Finland
Finland’s Criminal Code (1889), as amended in 2008, provides that any person who “initiates an attack that causes … extensive, long-term and serious environmental damage that [is] clearly excessive in comparison with the anticipated real and direct military benefit” shall be “sentenced for a war crime to imprisonment for at least one year or for life”. 
Finland, Criminal Code, 1889, as amended in 2008, Chapter 11, Section 5(1)(8).
(emphasis in original)
France
France’s Code of Defence (2004), as amended in 2008, states:
It is … prohibited [for combatants] to carry out an attack that may incidentally inflict widespread, long-term and severe damage to the natural environment which is excessive in relation to the military advantage anticipated. 
France, Code of Defence, 2004, as amended in 2008, Article D4122-10.
France
France’s Penal Code (1992), as amended in 2010, states in its section on war crimes related to international armed conflict:
Intentionally launching an attack in the knowledge that it will cause incidental … widespread, long-term and severe damage to the natural environment which would be clearly disproportionate in relation to the concrete and direct military advantage anticipated for the overall attack … is punishable by 20 years’ imprisonment. 
France, Penal Code, 1992, as amended in 2010, Article 461-28.
Georgia
Under Georgia’s Criminal Code (1999), any war crime provided for by the 1998 ICC Statute which is not explicitly mentioned in the Code is a crime, including “intentionally launching an attack in the knowledge that such attack will cause … widespread, long-term and severe damage to the natural environment which would be clearly excessive in relation to the concrete and direct overall military advantage anticipated” in international armed conflict. 
Georgia, Criminal Code, 1999, Article 413(d).
Germany
Germany’s Law Introducing the International Crimes Code (2002) provides:
Anyone who, in connection with an international armed conflict, carries out an attack with military means which may be expected to cause widespread, long-term and severe damage to the natural environment which could be excessive in relation to the overall concrete and direct military advantage anticipated, shall be liable to imprisonment for not less than three years. 
Germany, Law Introducing the International Crimes Code, 2002, Article 1, § 12(3).
Iraq
Iraq’s Law of the Supreme Iraqi Criminal Tribunal (2005) identifies the following as a serious violation of the laws and customs of war applicable in international armed conflicts:
Intentionally launching an attack in the knowledge that such attack will cause widespread, long-term and severe damage to the natural environment, which would be clearly excessive in relation to the concrete and direct overall military advantage anticipated. 
Iraq, Law of the Supreme Iraqi Criminal Tribunal, 2005, Article 13(2)(E).
Ireland
Under Ireland’s Geneva Conventions Act (1962), as amended in 1998, any “minor breach” of the 1977 Additional Protocol I, including violations of Articles 35(3) and 55(1), is a punishable offence. 
Ireland, Geneva Conventions Act, 1962, as amended in 1998, Section 4(1) and (4).
Netherlands
Under the International Crimes Act (2003) of the Netherlands, “intentionally launching an attack in the knowledge that such an attack will cause … widespread, long-term and severe damage to the natural environment which would be clearly excessive in relation to the concrete and direct overall military advantage anticipated” is a crime, when committed in an international armed conflict. 
Netherlands, International Crimes Act, 2003, Article 5(5)(b).
New Zealand
Under New Zealand’s International Crimes and ICC Act (2000), war crimes include the crimes defined in Article 8(2)(b)(iv) of the 1998 ICC Statute. 
New Zealand, International Crimes and ICC Act, 2000, Section 11(2).
Nicaragua
Nicaragua’s Military Penal Code (1996) punishes a soldier who
destroys or damages, without military necessity, … places of historical or environmental importance … and natural sites, gardens and parks of historical-artistic or anthropological value and, in general, all those which are part of the historical heritage. 
Nicaragua, Military Penal Code, 1996, Article 61.
Norway
Norway’s Military Penal Code (1902), as amended in 1981, provides:
Anyone who contravenes or is accessory to the contravention of provisions relating to the protection of persons or property laid down in … the two additional protocols to [the 1949 Geneva] Conventions … is liable to imprisonment. 
Norway, Military Penal Code, 1902, as amended in 1981, § 108(b).
Norway
Norway’s Penal Code (1902), as amended in 2008, states:
Any person is liable to punishment for a war crime who in connection with an armed conflict … launches an attack in the knowledge that such attack will cause … damage to the natural environment which would be excessive in relation to the concrete and direct overall military advantage anticipated. 
Norway, Penal Code, 1902, as amended in 2008, § 106(c).
Senegal
Senegal’s Penal Code (1965), as amended in 2007, states that the following constitutes a war crime:
b) [O]ther serious violations of the laws and customs applicable in international armed conflict, within the established framework of international law, namely, any of the following acts:
3. launching a deliberate attack in the knowledge that such attack will cause … widespread, long-term and severe damage to the natural environment which would be clearly excessive in relation to the concrete and direct overall military advantage anticipated. 
Senegal, Penal Code, 1965, as amended in 2007, Article 431-3(b)(3).
Slovakia
Slovakia’s Criminal Code (1961), as amended, provides for the punishment of “a commander who, contrary to the provisions of international law on means and methods of warfare, intentionally: … (d) destroys or damages … an internationally recognized … natural site”. 
Slovakia, Criminal Code, 1961, as amended, Article 262(2)(d).
South Africa
South Africa’s ICC Act (2002) reproduces the war crimes listed in the 1998 ICC Statute, including in international armed conflicts:
intentionally launching an attack in the knowledge that such attack will cause … widespread, long-term and severe damage to the natural environment which would be clearly excessive in relation to the concrete and direct overall military advantage anticipated. 
South Africa, ICC Act, 2002, Schedule 1, Part 3, § (b)(iv).
Spain
Spain’s Military Criminal Code (1985) punishes a soldier who:
destroys or damages, without military necessity, … places of historical or environmental importance … and natural sites, gardens and parks of historical-artistic or anthropological value and, in general, all those which are part of the historical heritage. 
Spain, Military Criminal Code, 1985, Article 77(7).
United Kingdom of Great Britain and Northern Ireland
Under the UK ICC Act (2001), it is a punishable offence to commit a war crime as defined in Article 8(2)(b)(iv) of the 1998 ICC Statute. 
United Kingdom, ICC Act, 2001, Sections 50(1) and 51(1) (England and Wales) and Section 58(1) (Northern Ireland).
Canada
In 2013, in the Sapkota case, Canada’s Federal Court dismissed a request for review of a decision denying refugee protection to the applicant on grounds of complicity in crimes against humanity in Nepal between 1991 and 2009. While reviewing the submissions of the respondent, Canada’s Minister of Citizenship and Immigration, the Court stated: “The Respondent notes that the Rome Statute of the International Criminal Court … is endorsed in Canada as a source of customary law.” 
Canada, Federal Court, Sapkota case, Reasons for Judgment and Judgment, 15 July 2013, § 28.
Democratic Republic of the Congo
In 2009, in the Basele Lutula and Others case, the Military Garrison Court of Kisangani convicted Mai-Mai militia members of various crimes. The Court stated:
Destruction and damage without malicious intent (article 113 of CPL II [Penal Code])
Pursuant to article 113 of the Penal Code enacted by the ordinance of 28 February 1913: “whoever, even without malicious intent, destroys or damages, without any right or title, … movable or immovable property is liable to punishment of up to seven days’ imprisonment and a fine … ”.
It follows from this definition that this offence requires the combination of the following constitutive elements: protected objects, a material act and a moral element.
Article 113 can be applied with regard to [the following protected objects]:
- fruit and ornamental … [trees]
- palm tree …
- immovable property (sites, caves, caverns … ) …
The law does not require that the destroyed or damaged property belongs to another person.
The material act consists of destroying or damaging the above-mentioned objects as specified by law.
The moral element which characterizes this offence … is a simple [and] general one. The agent must act voluntarily but without malicious intent or without title or right.
In the present case, the defendants Kipeleka Nyembo, Okanga Likunda, Osumaka Loleka and Koti Okeke knew that they were breaching the law when they were … cutting down fruit trees which are protected by law, namely mango, palm and avocado trees. 
Democratic Republic of the Congo, Military Garrison Court of Kisangani, Basele Lutula and Others case, Judgment, 3 June 2009, pp. 13–15.
United States of America
The Agent Orange case in 2005 involved a class action suit filed on behalf of various Vietnamese nationals and an organization, The Vietnamese Association for Victims of Agent Orange/Dioxin, against Dow Chemical and other US chemical manufacturers, for harms allegedly done to them and their land through the United States’ use of Agent Orange and other herbicides during the Vietnam War from 1965 to 1971 and by the South Vietnamese government’s subsequent use of such herbicides until 1975. In dismissing the claims, the Court found that, while recognizing the evolution of international law since 1975, the use of herbicides did not violate, at the time they were used, either customary or conventional international law binding on the United States. On the question of whether any source of international law in effect during the period 1961–1975 limited environmental damage during the conduct of hostilities, the Court stated:
Treaties limiting environmental damage in warfare were not in effect during the period of 1961–1975. The United States did not violate any such provision, defendants could not be held liable under them and plaintiffs could not state a claim under them. The United States signed Protocol Additional to the Geneva Conventions of 12 August 1949, and Relating to the Protection of Victims of International Armed Conflict (Protocol I), June 8, 1977, 1125 U.N.T.S. 3 (entered into force Dec. 7, 1978), on December 12, 1977, but never ratified it … While it might be interpreted to apply to future use of herbicides in the way they were used in Vietnam, it had no application prior to 1975. 
United States, Eastern States District Court (EDNY), Agent Orange case, Judgment, 28 March 2005, p. 207.
Argentina
In 1992, during a debate in the Sixth Committee of the UN General Assembly on protection of the environment in times of armed conflict, Argentina recommended that:
Belligerents engaged in an armed conflict, whether international or non-international, should always bear in mind that the protection of the environment affects the well-being of humanity as a whole. They should therefore use those means which are least apt to cause damage to the environment, damage for which they would be responsible. 
Argentina, Statement before the Sixth Committee of the UN General Assembly, UN Doc. A/C.6/47/SR.8, 1 October 1992, § 23.
Australia
In 1991, during a debate in the UN General Assembly on the environmental impact of the Gulf War, Australia insisted that “what had been done in Kuwait was clearly illegal under the customary rules of warfare and the traditional concepts of proportionality and military necessity”. 
Australia, Statement before the Sixth Committee of the UN General Assembly, UN Doc. A/C.6/46/SR.20, 22 October 1991, § 7.
Australia
In a briefing note in 1992, the Australian Department of Foreign Affairs and Trade stated that the Gulf War had underlined “the continuing need for the extension of principles of humanitarian law in cases of armed conflict”, and referred to “the environmental devastation caused by the deliberate creation of oil slicks by Iraqi forces”. 
Australia, Department of Foreign Affairs and Trade, DFAT-92/013031 Pt 8, 13 February 1991, p. 2, § 5.
Australia
In its oral pleadings before the ICJ in the Nuclear Weapons case in 1995, Australia stated: “In recent times the issue of the protection of the environment in armed conflict has been a particular international concern.” It referred to a number of international treaties, including the relevant provisions of the 1976 ENMOD Convention, the 1977 Additional Protocol I and the 1993 Chemical Weapons Convention. It stated that these instruments provided “cumulative evidence that weapons having … potentially disastrous effects on the environment, and on civilians and civilian targets, are no longer compatible with the dictates of public conscience” reflected in the general principles of humanity. Australia added that “consideration of lethal effects of radiation over time provides a link between the principle which provides for the protection of civilian populations and the principle which provides for protection of the environment”. 
Australia, Oral pleadings before the ICJ, Nuclear Weapons case, 30 October 1995, Verbatim Record CR 95/22, p. 47, § 31.
Austria
In 1991, during a debate in the Sixth Committee of the UN General Assembly on the protection of the environment in armed conflict, Austria stated, with respect to the damage caused by Iraq to the environment:
There could be no doubt whatsoever that those deliberate acts of environmental destruction flagrantly violated existing international law and could not, even in the most remote sense, be justified by military necessity … There could be no doubt as to the illegality of the acts committed by Iraq, entailing international responsibility of that State as well as personal criminal liability of those responsible for those acts. 
Austria, Statement before the Sixth Committee of the UN General Assembly, UN Doc. A/C.6/46/SR.19, 23 October 1991, § 5.
Austria
In 1992, during a debate in the UN General Assembly on the environmental impact of the Gulf War, Austria stated that it was a “shortcoming” of the present legal regime that “the principle of proportionality between the military necessity of an action and its possible detrimental effects on the environment was usually applied in favour of military necessity”. 
Austria, Statement before the Sixth Committee of the UN General Assembly, UN Doc. A/C.6/47/SR.8, 1 October 1992, § 37.
Brazil
In 1992, during a debate in the Sixth Committee of the UN General Assembly on protection of the environment in times of armed conflict, Brazil stated: “A principle of customary international law which, in general terms, protected the environment in times of armed conflict had been recognized implicitly in paragraph 39.6 of Agenda 21 of UNEP.” 
Brazil, Statement before the Sixth Committee of the UN General Assembly, UN Doc. A/C.6/47/SR.9, 6 October 1992, § 12.
Canada
In 1991, during a debate in the Sixth Committee of the UN General Assembly on the protection of the environment in armed conflict, Canada stated:
An important conclusion reached at the international conference of experts held at Ottawa [from 9–12 July 1991] was that the customary laws of war, in reflecting the dictates of public conscience, now included a requirement to avoid unnecessary damage to the environment … In effect, the practice of States, generally accepted environmental principles and public consciousness about the environment had combined with the traditional armed conflict rules on the protection of civilians and their property to produce a customary rule of armed conflict prohibiting the infliction of unnecessary damage on the environment in wartime. 
Canada, Statement before the Sixth Committee of the UN General Assembly, UN Doc. A/C.6/46/SR.18, 22 October 1991, §§ 13–14.
Canada
In 1992, during a debate in the Sixth Committee of the UN General Assembly on protection of the environment in times of armed conflict, Canada reiterated the conclusions of the Ottawa conference and referred to the rule of proportionality as “the need to strike a balance between the protection of the environment and the needs of war” and further concluded that, under the principle of distinction, “the environment as such should not form the object of direct attack”. 
Canada, Statement before the Sixth Committee of the UN General Assembly, UN Doc. A/C.6/47/SR.8, 1 October 1992, § 20.
Canada
At the Conference on Environmental Protection and the Law of War held in London in 1992, Canada, with reference to the Martens Clause, identified a “requirement to avoid unjustifiable damage to the environment”. 
Canada, Statement at the Conference on Environmental Protection and the Law of War, London, 3 June 1992.
Colombia
In 1996, a study of Colombia’s Presidential Council for Human Rights, conducted in cooperation with the Colombian Red Cross and the Jorge Tadeo Lozano University, asserted that “the principle of proportionality … [is] also directly applicable to the ecological heritage of the human race”. 
Colombia, Presidential Council for Human Rights in cooperation with the Colombian Red Cross and the Jorge Tadeo Lozano University, Academic Study on National Measures of Application of International Humanitarian Law, Bogotá, September 1996, p. 67.
Croatia
In 1992, in a letter to the President of the UN Security Council, Croatia stated: “Unprovoked, indiscriminate and savage attacks may result in an economic and ecological catastrophe which could happen if oil facilities on both sides of the river are destroyed.” 
Croatia, Letter dated 24 August 1992 to the President of the UN Security Council, UN Doc. S/24481, 25 August 1992, p. 2.
France
Upon ratification of the 1998 ICC Statute, France declared:
The risk of damage to the natural environment as a result of methods and means of warfare, as envisaged in article 8, paragraph 2 (b) (iv), must be weighed objectively on the basis of the information available at the time of its assessment. 
France, Interpretative declarations made upon ratification of the 1998 ICC Statute, 9 June 2000, § 7.
Islamic Republic of Iran
In 1991, during a debate in the Sixth Committee of the UN General Assembly on protection of the environment in armed conflict, the Islamic Republic of Iran stated:
Referring to the law of armed conflict, … both customary law and treaty law prohibited belligerent parties from inflicting either direct or indirect damage on the environment.
The principle of proportionality, which was enshrined in customary law, set important limits on warfare whereby damage not necessary to the achievement of a definite military advantage was prohibited. Another principle of customary law, whereby military operations not directed against military targets were prohibited, had been incorporated in the preamble of the 1868 Declaration of St. Petersburg to the effect of prohibiting the use of certain practices in wartime and in article 35.1 of [the 1977 Additional Protocol I]. Lastly, the [1907 Hague Regulations] prohibited the destruction of non-military enemy property unless imperatively demanded by the necessities of war … The Fourth Geneva Convention contained two provisions intended to ensure indirect protection of the environment in the context of protecting property rights in occupied territories. Thus, for example, an occupying Power which destroyed industrial installations in an occupied territory, causing damage to the environment, would be in violation of the Fourth Geneva Convention unless such destruction was justified by military necessity. If such destruction was extensive, it constituted a grave breach of the Convention and even a war crime. 
Islamic Republic of Iran, Statement before the Sixth Committee of the UN General Assembly, UN Doc. A/C.6/46/SR.18, 22 October 1991, §§ 27–28.
Islamic Republic of Iran
In its oral pleadings before the ICJ in the Nuclear Weapons case in 1995, the Islamic Republic of Iran argued:
As far as the law of armed conflict is concerned, both the customary rules and the provisions of treaty law prohibit belligerent parties, directly or indirectly, from inflicting unnecessary damage on the environment. Parties to the armed conflict are obliged, in accordance with well-established rules of customary law pertaining to armed conflict, to protect the environment in time of armed conflict. 
Islamic Republic of Iran, Oral pleadings before the ICJ, Nuclear Weapons case, 6 November 1995, Verbatim Record CR 95/26, p. 34, § 59.
Japan
In its oral pleadings before the ICJ in the Nuclear Weapons case in 1995, Japan expressed the view that, “in terms of international law concerning warfare, … the destruction of [the] natural environment [is] prohibited”. 
Japan, Oral pleadings before the ICJ, Nuclear Weapons case, 7 November 1995, Verbatim Record CR 95/27, p. 37.
Jordan
Prior to the adoption of UN General Assembly Resolution 47/37 in 1992 on the protection of the environment in times of armed conflict, Jordan and the United States submitted a memorandum to the Sixth Committee of the UN General Assembly entitled “International Law Providing Protection to the Environment in Times of Armed Conflict”. In it, they stated that “the customary rule that prohibits attacks which reasonably may be expected at the time to cause incidental loss of civilian life, injury to civilians, damage to civilian objects, or a combination thereof, which would be excessive in relation to the concrete and direct military advantage anticipated, are prohibited” provides protection for the environment in times of armed conflict. 
Jordan and United States, International Law Providing Protection to the Environment in Times of Armed Conflict, annexed to Letter dated 28 September 1992 to the Chairman of the Sixth Committee of the UN General Assembly, UN Doc. A/C.6/47/3, 28 September 1992, § 1(h).
Marshall Islands
In its oral pleadings before the ICJ in the Nuclear Weapons case in 1995, the Marshall Islands referred to the environmental damage caused by the use of nuclear weapons, remarking that such damage “should not be regarded as necessary to the achievement of military objectives”. 
Marshall Islands, Oral pleadings before the ICJ, Nuclear Weapons case, 14 November 1995, Verbatim Record CR 95/32, p. 22.
Romania
In 1994, Romania’s Ministry of Defence pointed out:
The education and instruction process was intended especially for the study and implementation of the types of military decisions that would provide a balance between the desired military advantage and its potentially negative impact on the environment. 
UN Secretary-General, Report on the United Nations Decade of International Law, UN Doc. A/49/323, 19 August 1994, § 32.
Russian Federation
In 1992, during a debate in the Sixth Committee of the UN General Assembly on protection of the environment in times of armed conflict, the Russian Federation insisted that “premeditated and indiscriminate destruction of the environment in times of armed conflict constituted not merely an evil but a crime”. It added that “such acts were clearly violations of the norms of international law and could not be justified even as reprisals”. 
Russian Federation, Statement before the Sixth Committee of the UN General Assembly, UN Doc. A/C.6/47/SR.9, 6 October 1992, p. 4, § 16.
Sweden
In 1991, during a debate in the Sixth Committee of the UN General Assembly on the environmental impact of the Gulf War, Sweden expressed the view that the destruction of the environment caused by Iraqi forces was taking place “on an unprecedented scale” and considered that it constituted “unacceptable forms of warfare in the future”. 
Sweden, Statement before the Sixth Committee of the UN General Assembly, UN Doc. A/C.6/46/SR.20, 22 October 1991, § 21.
Switzerland
Switzerland’s ABC of International Humanitarian Law (2009) states:
Civilian objects
International humanitarian law distinguishes between Civilian objects and Military objectives, prohibiting acts of violence against the former. Other provisions provide special protection for certain specific civilian objects, some of which are expected to bear distinctive signs: … the natural environment … . Civilian objects are all objects which are not military objectives.
Environment
Attacks and combat methods that can cause widespread, long-term and severe damage to the natural environment are expressly prohibited by the First Additional Protocol to the Geneva Conventions. The general principles of Customary international law such as the principles of Distinction and Proportionality ensure protection of the environment. 
Switzerland, Federal Department of Foreign Affairs, ABC of International Humanitarian Law, 2009, pp. 12 and 20.
United Kingdom of Great Britain and Northern Ireland
In a briefing note in 1991, the UK Foreign and Commonwealth Office declared that Iraq’s attacks on Kuwaiti oil fields were “a deliberate crime against the planet”. 
United Kingdom, Foreign and Commonwealth Office, Briefing Note: Oil Pollution in the Gulf, June 1991, reprinted in Marc Weller (ed.), Iraq and Kuwait: The Hostilities and Their Aftermath, Grotius Publications, Cambridge, 1993, p. 338.
United States of America
In 1991, during a debate in the Sixth Committee of the UN General Assembly on the protection of the environment in armed conflict, the United States stated:
The deliberate release of oil into the Gulf and the burning of Kuwaiti oil wells had constituted a serious violation of the prohibition of the destruction of property unless required by military necessity contained in [the 1949 Geneva Convention IV and the 1907 Hague Regulations]. Those acts had also been a violation of the prohibitions under customary international law against any military operation which was not directed against a legitimate military target or which could be expected to cause incidental death, injury or damage to civilians that was clearly excessive in relation to the direct military advantage of the operation. In the situation under consideration, the oil well destruction had taken place at a time when it had been clear to Iraq that the war had ended … Those violations of international law had definite legal consequences, as [the 1949 Geneva Convention IV] acknowledged in stipulating that the destruction of property not justified by military necessity was a grave breach and that persons committing such breaches incurred criminal liability … Iraq’s actions did not demonstrate that existing international law was inadequate, but, rather, that the problem involved compliance with existing law, and no new rule or conventions were needed. 
United States, Statement before the Sixth Committee of the UN General Assembly, UN Doc. A/C.6/ 46/SR.18, 22 October 1991, §§ 37–40.
United States of America
In 1992, during the debate in the Sixth Committee of the UN General Assembly on protection of the environment in time of armed conflict, the United States stated: “In time of war some collateral damage to the environment … is inevitable.” 
United States, Statement before the Sixth Committee of the UN General Assembly, UN Doc. A/C.6/ 47/SR.9, 6 October 1992, § 55.
United States of America
In 1992, in its final report to Congress on the conduct of hostilities in the Gulf War, the US Department of Defence considered that the destruction of oil well heads and the release of crude oil into the Gulf by Iraq violated Article 23(g) of the 1907 Hague Regulations and Article 147 of the 1949 Geneva Convention IV. It further stated:
As the first Kuwaiti oil wells were ignited by Iraqi forces, there was public speculation the fires and smoke were intended to impair Coalition forces’ ability to conduct both air and ground operations, primarily by obscuring visual and electro-optical sensing devices. Review of Iraqi actions makes it clear the oil well destruction had no military purpose, but was simply punitive destruction at its worst. For example, oil well fires to create obscurants could have been accomplished simply through the opening of valves; instead, Iraqi forces set explosive charges on many wells to ensure the greatest possible destruction and maximum difficulty in stopping each fire. Likewise, the Ar-Rumaylah oil field spreads across the Iraq-Kuwait border. Had the purpose of the fires been to create an obscurant, oil wells in that field on each side of the border undoubtedly would have been set ablaze; Iraqi destruction was limited to oil wells on the Kuwaiti side only. As with the release of oil into the Persian Gulf, this aspect of Iraq’s wanton destruction of Kuwaiti property had little effect on Coalition offensive combat operations. In fact, the oil well fires had a greater adverse effect on Iraqi military forces. 
United States, Department of Defence, Final Report to Congress on the Conduct of the Persian Gulf War, 10 April 1992, Appendix O, The Role of the Law of War, ILM, Vol. 31, pp. 636–637.
United States of America
Prior to the adoption of UN General Assembly Resolution 47/37 in 1992 on the protection of the environment in times of armed conflict, Jordan and the United States submitted a memorandum to the Sixth Committee of the UN General Assembly entitled “International Law Providing Protection to the Environment in Times of Armed Conflict”. In it, they stated that “the customary rule that prohibits attacks which reasonably may be expected at the time to cause incidental loss of civilian life, injury to civilians, damage to civilian objects, or a combination thereof, which would be excessive in relation to the concrete and direct military advantage anticipated, are prohibited” provides protection for the environment in times of armed conflict.  
Jordan and United States, International Law Providing Protection to the Environment in Times of Armed Conflict, annexed to Letter dated 28 September 1992 to the Chairman of the Sixth Committee of the UN General Assembly, UN Doc. A/C.6/47/3, 28 September 1992, § 1(h).
United States of America
In 1993, in a report to Congress on international policies and procedures regarding the protection of natural and cultural resources during times of war, the US Department of Defense stated:
The United States considers the obligations to protect natural, civilian, and cultural property to customary international law … Natural resources are protected from intentional attack so long as they are not utilized for military purposes … The United States recognizes that protection of natural resources, as well as protection of the environment, is important even in times of armed conflict. Natural resources are finite, and reasonable measures must be taken to protect against their unnecessary destruction … What is prohibited is unnecessary destruction, that is destruction of natural resources that has no or limited military value. 
United States, Department of Defense, Report to Congress on International Policies and Procedures Regarding the Protection of Natural and Cultural Resources During Times of War, 19 January 1993, pp. 202–204.
United States of America
According to the Report on US Practice, it is the opinio juris of the United States that “collateral environmental damage caused by otherwise lawful military operations should be assessed for its proportionality to the expected military value of such operations”. 
Report on US Practice, 1997, Chapter 4.5.
United States of America
In 2005, the US Department of Justice submitted a Statement of Interest of the United States to the US District Court for the Eastern District of New York prior to that Court’s consideration of Agent Orange Product Liability Litigation (The Vietnam Association for Victims of Agent Orange/Dioxin, et al. v. Dow Chemical Company, et al.). In that statement, the Department of Justice's reiterated the US position that no rule of international law barred the use of chemical herbicides in war generally nor barred the destruction of crops intended for use by enemy forces. With regard to the military necessity for attacks against the natural environment, it stated:
The decision to use chemical herbicides was made by President Kennedy upon a recommendation by Secretary of State Rusk that “successful plant-killing operations in Viet-Nam, carefully coordinated with and incidental to larger operations, can be of substantial assistance in the control and defeat of the Viet Cong.” Rusk Memorandum. There can be little doubt that, as the then-Acting Assistant Secretary of Defense testified before Congress, the “use of… herbicides [in Vietnam] . .. had one purpose – to [s]ave the lives of Americans and those of our allies.” 1974 House Hearings at 154 (Statement of Amos Jordan, Acting Assistant Secretary for International Security Affairs, Department of Defense). Thus, as the Second Circuit has recognized, “at issue is a decision of the veterans’ highest military superiors that was designed to help, the veterans in fighting the armed conflict in which they were engaged.” FTCA/Feres Opinion. 818 F.2d at 200. 
United States, Department of Justice, Statement of Interest of the United States submitted to the US District Court for the Eastern District of New York, In re: Agent Orange Product Liability Litigation (The Vietnam Association for Victims of Agent Orange/Dioxin, et al. v. Dow Chemical Company, et al), 12 January 2005,§ II, p. 17.
The United States Use of Chemical Herbicides in Vietnam Did Not Violate Any Other Specifically Defined Norm
To the extent that plaintiffs’ claims are based not on the alleged per se illegality of the use of chemical herbicides in war, but rather on the specific manner in which the United States used such herbicides in Vietnam – i.e., to the extent that plaintiffs are alleging that the United States used a legal weapon in an illegal maimer – their claims must also fail, because no specifically defined norm barred the United States’ actions. In this regard, plaintiffs allege that the United States’ use of chemical herbicides violated the laws of war by, inter alia, causing “the wanton destruction of cities, towns, villages, or the natural environment, or devastation not justified by military necessity.” Am.Compl., ¶ 261. Presumably, plaintiffs are relying on the prohibitions in the 1907 Hague Convention against the destruction of enemy property “unless such destruction or seizure be imperatively demanded by the necessities of war.” 1907 Hague Convention, art. 23(g). The United States recognizes that the principles of necessity and proportionality – i.e., the requirements that no other means exist to achieve the desired military advantage and that civilian damage not be disproportional to military advantage – have attained the status of customary international law.
Pursuant to Sosa Sosa v. Alvarez-Machain, US Supreme Court, 2004] however, that is only the beginning of the inquiry. For there remains the question of whether the principles, as accepted by the international community, are defined with sufficient “specificity” comparable to the 18th Century paradigms noted in Sosa so as to allow for a cause of action under federal common law. In Sosa. the Court found that the claim of arbitrary detention had not achieved the status of a well-defined international law principle such that it could be enforced under the ATS [Alien Tort Statute]. The Supreme Court explained that any consensus concerning this norm was “at a high level of generality.” Sosa, 124 S. Ct. at 2768 n.27. The same is true here. There are simply no established international law standards of the specificity required by Sosa for establishing a federal common law cause of action for unnecessary or disproportionate use of military force.
Indeed, the very nature of the principles defy specificity, for they require the balancing of competing considerations and are inherently imprecise. That is, the rules do not proscribe any particular conduct that is readily identifiable. Rather, they require consideration by combatant commanders of a variety of factors – unique to the context of any particular military action – that affect decisions on what means may be available to achieve the military objective and whether the harms that particular military actions might cause would be disproportionate to the advantages attained. In light of the balancing nature of the principles, the very same act that might be deemed both necessary and proportionate in one circumstance, might be deemed unnecessary or disproportionate in another. It is one thing, therefore, to recognize that these principles generally exist in customary international law. It is “harder,” if not impossible, to “say which policies cross [the] line with the certainty afforded by Blackstone’s three common law offenses” 124 S. Ct. at 2769.
A recent report by a Committee established to review the NATO bombing campaign in Yugoslavia provides a good illustration of the imprecise nature of the rule of proportionality:
The main problem with the principle of proportionality is not whether or not it exists but what it means and how it is to be applied. It is relatively simple to state that there must be an acceptable relation between the legitimate destructive effect and undesirable collateral effects. For example, bombing a refugee camp is obviously prohibited if its only military significance is that people in the camp are knitting socks for soldiers. Conversely, an air strike on an ammunition dump should not be prohibited merely because a farmer is plowing a field in the area. Unfortunately, most applications of the principle of proportionality are not quite so clear cut. It is much easier to formulate the principle of proportionality in general terms than it is to apply it to a particular set of circumstances because the comparison is often between unlike quantities and values. One cannot easily assess the value of innocent human lives as opposed to capturing a particular military objective.
Final Report to the Prosecutor by the Committee Established to Review the NATO Bombing Campaign Against the Federal Republic of Yugoslavia ¶ 48 …
Because any consensus regarding the necessity and proportionality principles necessarily exists solely “at a high level of generality,” id at 2768 n.27, and because the principles are not “defined with … specificity,” id at 2761, and clearly have “less definite content” than the 18th Century offenses discussed in Sosa. id. at 2765, the Court should not recognize a federal common law cause of action for alleged violations of the necessity and proportionality principles. See also Flores. 343 F.3d at 160–61. 
United States, Department of Justice, Statement of Interest of the United States submitted to the US District Court for the Eastern District of New York, In re: Agent Orange Product Liability Litigation (The Vietnam Association for Victims of Agent Orange/Dioxin, et al. v. Dow Chemical Company, et al), 12 January 2005,§ II, pp. 33–36.
UN General Assembly
In a resolution adopted in 1992 on protection of the environment in times of armed conflict, the UN General Assembly:
Expressing its deep concern about environmental damage and depletion of natural resources, including the destruction of hundreds of oil-well heads and the release and waste of crude oil into the sea, during recent conflicts,
Noting that existing provisions of international law prohibit such acts,
Stressing that destruction of the environment, not justified by military necessity and carried out wantonly, is clearly contrary to existing international law,
1. Urges States to take all measures to ensure compliance with the existing international law applicable to the protection of the environment in times of armed conflict. 
UN General Assembly, Res. 47/37, 25 November 1992, preamble and § 1, adopted without a vote.
UN General Assembly
In a resolution adopted in 1994 on the United Nations Decade of International Law, the UN General Assembly referred to the 1994 Guidelines on the Protection of the Environment in Times of Armed Conflict and invited
all States to disseminate widely the revised guidelines for military manuals and instructions on the protection of the environment in times of armed conflict received from the International Committee of the Red Cross and to give due consideration to the possibility of incorporating them into their military manuals and other instructions addressed to their military personnel. 
UN General Assembly, Res. 49/50, 9 December 1994, § 11, adopted without a vote.
UN General Assembly
The programme of activities for the final term (1997–1999) of the UN Decade of International Law, adopted by the UN General Assembly in 1996, states:
In connection with training of military personnel, States are encouraged to foster the teaching and dissemination of the principles governing the protection of the environment in times of armed conflict and should consider the possibility of making use of the guidelines for military manuals and instructions prepared by the International Committee of the Red Cross. 
UN General Assembly, Res. 51/157, 16 December 1996, Annex, § 19, adopted without a vote.
North Atlantic Treaty Organisation
In the context of NATO’s campaign against the Federal Republic of Yugoslavia, following NATO’s air strikes on the industrial complex in Pancevo on 18 April 1999, which resulted in the emission of chemical substances into the air and water, a NATO spokesperson argued that the industrial site was to be considered as a “strategic target”, as it was “a key installation” that provided petrol and other resources to support the Yugoslav army. The official said that the environmental damage caused by the attack was taken into consideration, explaining that “when targeting is done we take into account all possible collateral damage, be it environmental, human or to the civilian infrastructure”. 
Chris Hedges, “Serbian Town Bombed by NATO Fears Effects of Toxic Chemicals”, New York Times, 14 July 1999.
North Atlantic Treaty Organisation
At a press conference held at NATO Headquarters in Brussels on 20 April 1999 during NATO’s military operations against the Federal Republic of Yugoslavia, a General, asked to comment on NATO’s bombing of a chemical factory in Baric, which caused threats to the environment, declared: “Every single target is chosen having great consideration for possible collateral damage.” He then stated: “The fact that a chemical factory has been hit does not mean that this process has been disregarded in this instance.” 
NATO, Press Conference by Jamie Shea and Brigadier General Giuseppe Marani, NATO Headquarters, Brussels, 20 April 1999.
Expert Meeting on the Protection of the Environment in Time of Armed Conflict
In 1992, in a report submitted to the UN Secretary-General on the protection of the environment in time of armed conflict, the ICRC described the outcome of an expert meeting it organized on this subject in Geneva from 27 to 29 April 1992, stating:
The participants stressed the need to take environmental protection into account when assessing the military advantages to be expected from an operation. They reaffirmed the importance and relevance with regard to environmental protection of the accepted principles concerning the conduct of hostilities. These include:
(a) The prohibition of actions causing damage that is not warranted by military necessity;
(b) The obligation, when possible, to choose the least harmful means of reaching a military objective;
(c) The obligation to respect proportionality between the military advantage expected and the incidental damage to the environment. 
ICRC, Report on the Protection of the Environment in Time of Armed Conflict submitted to the UN General Assembly, reprinted in Report of the UN Secretary-General on the protection of the environment in times of armed conflict, UN Doc. A/47/328, 31 July 1992, § 54.
International Conference for the Protection of War Victims
The Final Declaration adopted by the International Conference for the Protection of War Victims in 1993 urged all States to make every effort to:
Reaffirm and ensure respect for the rules of international humanitarian law applicable during armed conflicts protecting … the natural environment, either against attacks on the environment as such or against wanton destruction causing serious environmental damage; and continue to examine the opportunity of strengthening them. 
International Conference for the Protection of War Victims, Geneva, 30 August–1 September 1993, Final Declaration, § II(10), ILM, Vol. 33, 1994, p. 301.
International Court of Justice
In its advisory opinion in the Nuclear Weapons case in 1996, the ICJ did not directly deal with the issue of the precise extent to which environmental treaties applied during armed conflict, but stated in general terms:
The Court does not consider that the treaties in question could have intended to deprive a State of the exercise of its right of self-defence under international law because of its obligations to protect the environment. Nonetheless, States must take environmental considerations into account when assessing what is necessary and proportionate in the pursuit of legitimate military objectives. Respect for the environment is one of the elements that go to assessing whether an action is in conformity with the principle of necessity. 
ICJ, Nuclear Weapons case, Advisory Opinion, 8 July 1996, § 30.
The ICJ noted that this approach was supported by Principle 24 of the 1992 Rio Declaration, and also cited with approval UN General Assembly Resolution 47/37, which stated that “destruction of the environment, not justified by military necessity and carried out wantonly, is clearly contrary to existing law”. 
ICJ, Nuclear Weapons case, Advisory Opinion, 8 July 1996, § 32.
More generally, the Court found that international environmental law “indicates important factors that are properly to be taken into account in the context of the implementation of the principles and rules of the law applicable in armed conflict”. 
ICJ, Nuclear Weapons case, Advisory Opinion, 8 July 1996, § 33.
International Criminal Tribunal for the former Yugoslavia
In its Final Report to the ICTY Prosecutor in 2000, the Committee Established to Review the NATO Bombing Campaign Against the Federal Republic of Yugoslavia remarked that Articles 35(3) and 55 of the 1977 Additional Protocol I had “a very high threshold of application” which made it very difficult to assess whether environmental damage had exceeded the threshold of the Protocol. For this reason, in the Committee’s view, the environmental impact of the NATO bombing campaign was “best considered from the underlying principles of the law of armed conflicts such as necessity and proportionality”. 
ICTY, Final Report to the Prosecutor by the Committee Established to Review the NATO Bombing Campaign Against the Federal Republic of Yugoslavia, 14 June 2000, § 15.
As to the application of the principle of proportionality, the Committee stressed that:
18. … Even when targeting admittedly legitimate military objectives, there is a need to avoid excessive long-term damage to … natural environment with a consequential adverse effect on the civilian population. Indeed, military objectives should not be targeted if the attack is likely to cause collateral environmental damage which would be excessive in relation to the direct military advantage which the attack is expected to produce.
22. … In order to satisfy the requirement of proportionality, attacks against military targets which are known or can reasonably be assumed to cause grave environmental harm may need to confer a very substantial military advantage in order to be considered legitimate. At a minimum, actions resulting in massive environmental destruction, especially where they do not serve a clear and important military purpose, would be questionable. The targeting by NATO of Serbian petro-chemical industries may well have served a clear and important military purpose.
23. The above considerations also suggest that the requisite mens rea on the part of a commander would be actual or constructive knowledge as to the grave environmental effects of a military attack; a standard which would be difficult to establish for the purposes of prosecution and which may provide an insufficient basis to prosecute military commanders inflicting environmental harm in the (mistaken) belief that such conduct was warranted by military necessity … In addition, the notion of “excessive” environmental destruction is imprecise and the actual environmental impact, both present and long term, of the NATO bombing campaign is at present unknown and difficult to measure.
24. In order to fully evaluate such matters, it would be necessary to know the extent of the knowledge possessed by NATO as to the nature of Serbian military-industrial targets (and thus, the likelihood of environmental damage flowing from their destruction), the extent to which NATO could reasonably have anticipated such environmental damage (for instance, could NATO have reasonably expected that toxic chemicals of the sort allegedly released into the environment by the bombing campaign would be stored alongside that military target?) and whether NATO could reasonably have resorted to other (and less environmentally damaging) methods for achieving its military objective of disabling the Serbian military-industrial infrastructure. 
ICTY, Final Report to the Prosecutor by the Committee Established to Review the NATO Bombing Campaign Against the Federal Republic of Yugoslavia, 14 June 2000, §§ 18 and 22–24.
ICRC
To fulfil its task of disseminating IHL, the ICRC has delegates around the world teaching armed and security forces that: “To fulfil his mission, the commander needs appropriate information about the enemy and the environment. To comply with the law of war, information must include: … e) natural environment”. 
Frédéric de Mulinen, Handbook on the Law of War for Armed Forces, ICRC, Geneva, 1987, § 391.
ICRC
In an appeal issued in 1991 in the context of the Gulf War, the ICRC reminded the belligerents that: “Weapons having indiscriminate effects and those likely to cause disproportionate suffering and damage to the environment are prohibited.” 
ICRC, Press Release No. 1659, Middle East Conflict: ICRC appeals to belligerents, 1 February 1991, IRRC, No. 280, 1991, p. 27.
ICRC
In 1992, in a report submitted to the UN Secretary-General on the protection of the environment in time of armed conflict, the ICRC stated:
5. Since its inception, international humanitarian law has set limits on the right of belligerents to cause suffering and injury to people and to wreak destruction on objects, including objects belonging to the natural environment, and has traditionally been concerned with limiting the use of certain kinds of weapons or means of warfare which continue to damage even after the war is over, or which may injure people or property of States which are completely uninvolved in the conflict.
6. [reference to the 1868 St. Petersburg Declaration]
7. [reference to Article 35(1) of the 1977 Additional Protocol I]
8. The concept of proportionality also sets important limits on warfare: the only acts of war permitted are those that are proportional to the lawful objective of a military operation and actually necessary to achieve that objective.
9. These fundamental rules are now part of customary international law, which is binding on the whole community of nations. They are also applicable to the protection of the environment against acts of warfare. 
ICRC, Report on the Protection of the Environment in Time of Armed Conflict submitted to the UN General Assembly, reprinted in Report of the UN Secretary-General on the protection of the environment in times of armed conflict, UN Doc. A/47/328, 31 July 1992, §§ 5–9.
ICRC
In 1993, in a report submitted to the UN General Assembly on the protection of the environment in times of armed conflict, the ICRC stated:
Because [the 1977 Additional Protocol I], as at present, interpreted, does not necessarily cover all cases of damage to the environment and because not all States are party to it, the earlier conventional and customary rules, especially those of The Hague (1907) and Geneva (1949), continue to be very important. 
ICRC, Report on the protection of the environment in time of armed conflict submitted to the UN General Assembly, reprinted in Report of the UN Secretary-General on the protection of the environment in times of armed conflict, UN Doc. A/48/269, 29 July 1993, § 34.
With respect to the issue of the protection of the environment in non-international armed conflict, the report further states:
Although neither article 3 common to the 1949 Geneva Conventions nor [the 1977 Additional Protocol II] established a specific protection for the environment in times of non-international armed conflict, the environment is none the less protected by general rules of international humanitarian law [indiscriminate means and methods of warfare, proportionality, wanton destruction of property]. Among them, it is worth mentioning articles 14 and 15 of Protocol II of 1977, and provisions of the World Heritage Convention of 1972. The latter, applicable in all armed conflicts, could play an important role; greater efforts should therefore be made to ensure its full implementation. 
ICRC, Report on the protection of the environment in time of armed conflict submitted to the UN General Assembly, reprinted in Report of the UN Secretary-General on the protection of the environment in times of armed conflict, UN Doc. A/48/269, 29 July 1993, § 95.
Rogers
A.P.V. Rogers stated:
Environmental concerns certainly affected allied military planning [during the Gulf War]. It is reported that the allies decided not to attack four Iraqi super-tankers inside the Gulf which were contravening UN Security Council Resolution 665 because of the environmental consequences of so doing. 
A.P.V. Rogers, Law on the Battlefield, Manchester University Press, Manchester, 1996, p. 120.
International Institute of Humanitarian Law
During a meeting of the Institute of International Humanitarian Law held in 1993 as part of the process which resulted in the drafting of the 1994 San Remo Manual, a special rapporteur on the protection of the environment in armed conflict stated that the new wording of paragraph 44.5 of the manual stating that “damage to or destruction of the natural environment not justified by military necessity and carried out wantonly is prohibited” was a
response to the concern expressed by a number of participants … that, within the limits of the principle of military necessity, the draft should outlaw the use of the marine environment as an instrument of warfare or as a direct target or object of attack during an armed conflict at sea. 
Louise Doswald-Beck (ed.), San Remo Manual on International Law Applicable to Armed Conflicts at Sea, Cambridge University Press, Cambridge, 1995, p. 119, Explanation, § 44.5.
International Union for the Conservation of Nature
In 1995, the IUCN Commission on Environmental Law, in cooperation with the International Council of Environmental Law, issued the Draft International Covenant on Environment and Development, which was intended to stimulate consideration of a global instrument on environmental conservation and sustainable development. Article 32(2) provides:
Parties shall co-operate to further develop and implement rules and measures to protect the environment during international armed conflict and establish rules and measures to protect the environment during non-international armed conflict. 
IUCN, Commission on Environmental Law, Draft International Covenant on Environment and Development, Bonn, March 1995, Article 32(2).
The commentary on this draft provision notes:
Paragraph 2 aims at the further development of the law on this subject, both to deal with international armed conflict and non-international armed conflict. In the latter case, there is a particularly glaring dearth of law which must be remedied. 
IUCN, Commission on Environmental Law, Draft International Covenant on Environment and Development, Bonn, March 1995, Commentary on Article 32(2).