Rule 15. Precautions in Attack
Rule 15. In the conduct of military operations, constant care must be taken to spare the civilian population, civilians and civilian objects. All feasible precautions must be taken to avoid, and in any event to minimize, incidental loss of civilian life, injury to civilians and damage to civilian objects.
Summary
State practice establishes this rule as a norm of customary international law applicable in both international and non-international armed conflicts. The two components of this rule are interrelated and the practice pertaining to each reinforces the validity of the other. This is a basic rule to which more content is given by the specific obligations contained in Rules16–21. The practice collected in terms of those specific obligations is also relevant to prove the existence of this rule and vice versa.
International armed conflicts
The principle of precautions in attack was first set out in Article 2(3) of the 1907 Hague Convention (IX), which provides that if for military reasons immediate action against naval or military objectives located within an undefended town or port is necessary, and no delay can be allowed the enemy, the commander of a naval force “shall take all due measures in order that the town may suffer as little harm as possible”.[1]  It is now more clearly codified in Article 57(1) of Additional Protocol I, to which no reservations have been made.[2] 
The obligation to take constant care and/or to take precautions to avoid or minimize incidental civilian losses is contained in numerous military manuals.[3]  It is also supported by official statements and reported practice.[4]  This practice includes that of States not, or not at the time, party to Additional Protocol I.[5]  When the ICRC appealed to the parties to the conflict in the Middle East in October 1973, i.e., before the adoption of Additional Protocol I, to respect the obligation to take precautions in attack, the States concerned (Egypt, Iraq, Israel and Syrian Arab Republic) replied favourably.[6] 
Non-international armed conflicts
The requirement to take precautions in attack was included in the draft of Additional Protocol II but was dropped at the last moment as part of a package aimed at the adoption of a simplified text.[7]  As a result, Additional Protocol II does not explicitly require such precautions. Article 13(1), however, requires that “the civilian population and individual civilians shall enjoy general protection against the dangers arising from military operations”, and it would be difficult to comply with this requirement without taking precautions in attack.[8]  More recent treaty law applicable in non-international armed conflicts, namely Amended Protocol II to the Convention on Certain Conventional Weapons and the Second Protocol to the Hague Convention for the Protection of Cultural Property, does spell out the requirement of precautions in attack.[9]  In addition, this requirement is contained in other instruments pertaining also to non-international armed conflicts.[10] 
The obligation to take constant care and/or to take precautions to avoid or minimize incidental civilian losses is contained in military manuals which are applicable in or have been applied in non-international armed conflicts.[11]  There are a number of official statements pertaining to armed conflicts in general or to non-international armed conflicts in particular that refer to this requirement.[12] 
In 1965, the 20th International Conference of the Red Cross adopted a resolution calling on governments and other authorities responsible for action in all armed conflicts to spare the civilian population as much as possible.[13]  This was subsequently reaffirmed by the UN General Assembly in a resolution on respect for human rights in armed conflict adopted in 1968.[14]  Furthermore, in a resolution adopted in 1970 on basic principles for the protection of civilian populations in armed conflicts, the General Assembly required that “in the conduct of military operations, every effort should be made to spare civilian populations from the ravages of war, and all necessary precautions should be taken to avoid injury, loss or damage to civilian populations”.[15] 
The jurisprudence of the International Criminal Tribunal for the former Yugoslavia in the Kupreškić case and the Inter-American Commission on Human Rights in the case concerning the events at La Tablada in Argentina provides further evidence of the customary nature of this rule in both international and non-international armed conflicts.[16]  In the Kupreškić case, the Tribunal found the requirement to take precautions in attack to be customary because it specified and fleshed out general pre-existing norms.[17]  It can be argued indeed that the principle of distinction, which is customary in international and non-international armed conflicts, inherently requires respect for this rule. The Tribunal also relied on the fact that the rule had not been contested by any State.[18]  This study found no official contrary practice either.
The ICRC has appealed to parties to both international and non-international armed conflicts to respect the requirement to take precautions in attack.[19] 
Feasibility of precautions in attack
The obligation to take all “feasible” precautions has been interpreted by many States as being limited to those precautions which are practicable or practically possible, taking into account all circumstances ruling at the time, including humanitarian and military considerations.[20]  Protocols II and III and Amended Protocol II to the Convention on Certain Conventional Weapons define feasible precautions in the same terms.[21] 
Upon ratification of Additional Protocol I, Switzerland stated that the obligation imposed by Article 57(2) on “those who plan or decide upon an attack” to take the specific precautionary measures set out in the article creates obligations only for “commanding officers at the battalion or group level and above”.[22]  It previously expressed its concern at the Diplomatic Conference leading to the adoption of the Additional Protocols that the wording in the chapeau of Article 57(2) was ambiguous and “might well place a burden of responsibility on junior military personnel which ought normally to be borne by those of higher rank”.[23]  Also at the Diplomatic Conference, Austria expressed the same concern that “junior military personnel could not be expected to take all the precautions prescribed, particularly that of ensuring respect for the principle of proportionality during an attack”.[24]  Upon ratification of Additional Protocol I, the United Kingdom made a similar point with respect to the obligation to cancel or suspend an attack if it becomes clear that the target is not a military objective or that its attack is likely to cause excessive civilian damage (see Rule 19) to the effect that this obligation only applied to “those who have the authority and practical possibility to cancel or suspend the attack”.[25] 
Information required for deciding upon precautions in attack
Numerous States have expressed the view that military commanders and others responsible for planning, deciding upon or executing attacks necessarily have to reach decisions on the basis of their assessment of the information from all sources which is available to them at the relevant time.[26]  At the same time, many military manuals stress that the commander must obtain the best possible intelligence, including information on concentrations of civilian persons, important civilian objects, specifically protected objects, the natural environment and the civilian environment of military objectives.[27] 

[1] 1907 Hague Convention (IX), Article 2(3) (cited in Vol. II, Ch. 5, § 63).
[2] Additional Protocol I, Article 57(1) (adopted by 90 votes in favour, none against and 4 abstentions) (ibid., § 1).
[3] See, e.g., the military manuals of Australia (ibid., §§ 6 and 71), Belgium (ibid., §§ 7 and 72), Benin (ibid., §§ 8 and 73), Cameroon (ibid., § 9), Canada (ibid., §§ 10 and 74), Croatia (ibid., §§ 11 and 75–76), Ecuador (ibid., §§ 12 and 77), France (ibid., §§ 13 and 78), Germany (ibid., §§ 14 and 79), Hungary (ibid., §§ 15 and 80), Israel (ibid., § 16), Italy (ibid., §§ 17 and 81), Kenya (ibid., § 82), Madagascar (ibid., §§ 18 and 83), Netherlands (ibid., §§ 19–20 and 84), New Zealand (ibid., §§ 21 and 85), Nigeria (ibid., §§ 22–23 and 86), Philippines (ibid., § 87), Romania (ibid., § 24), Spain (ibid., §§ 25 and 88), Sweden (ibid., § 26), Switzerland (ibid., § 89), Togo (ibid., §§ 27 and 90), United Kingdom (ibid., § 91) and United States (ibid., §§ 28–29 and 92–94).
[4] See, e.g., the statements of Costa Rica (ibid., § 99), Israel (ibid., § 101), Liberia (ibid., § 36), Netherlands (ibid., §§ 38 and 105), Saudi Arabia (ibid., § 106), South Africa (ibid., § 39), United Kingdom (ibid., §§ 41 and 108–111) and United States (ibid., §§ 42 and 112–124) and the reported practice of Indonesia (ibid., §§ 35 and 100), Israel (ibid., § 102), Jordan (ibid., § 103), Malaysia (ibid., §§ 37 and 104), Syrian Arab Republic (ibid., §§ 40 and 107), United States (ibid., § 125) and Zimbabwe (ibid., § 126).
[5] See, e.g., the practice and reported practice of Indonesia (ibid., §§ 35 and 100), Israel (ibid., §§ 16 and 101–102), Kenya (ibid., § 82), Malaysia (ibid., §§ 37 and 104), Philippines (ibid., § 87), South Africa (ibid., § 39), United Kingdom (ibid., §§ 41, 91 and 108–111) and United States (ibid., §§ 28–29, 42, 92–94 and 112–125).
[6] See ICRC, The International Committee’s Action in the Middle East (ibid., § 51).
[7] Draft Additional Protocol II submitted by the ICRC to the Diplomatic Conference leading to the adoption of the Additional Protocols, Article 24(2) (ibid., § 3).
[8] Additional Protocol II, Article 13(1) (adopted by consensus) (ibid., § 2).
[9] Amended Protocol II to the Convention on Certain Conventional Weapons, Article 3(10) (cited in Vol. II, Ch. 28, § 4); Second Protocol to the Hague Convention for the Protection of Cultural Property, Article 7 (cited in Vol. II, Ch. 5, § 208).
[10] See, e.g., Memorandum of Understanding on the Application of IHL between Croatia and the Socialist Federal Republic of Yugoslavia, § 6 (ibid., §§ 4 and 67); Agreement on the Application of IHL between the Parties to the Conflict in Bosnia and Herzegovina, § 2.5 (ibid., §§ 5 and 68); CSCE Code of Conduct, § 36 (ibid., § 69); UN Secretary-General’s Bulletin, Section 5.3 (ibid., § 70).
[11] See, e.g., the military manuals of Benin (ibid., §§ 8 and 73), Croatia (ibid., §§ 11 and 75), Ecuador (ibid., §§ 12 and 77), Germany (ibid., §§ 14 and 79), Italy (ibid., §§ 17 and 81), Madagascar (ibid., §§ 18 and 83), Nigeria (ibid., §§ 22–23 and 86) and Togo (ibid., §§ 27 and 90).
[12] See, e.g., the statements of Bosnia and Herzegovina, Republika Srpska (ibid., § 34), Colombia (ibid., § 98), Liberia (ibid., § 36), Malaysia (ibid., § 104), United Kingdom (ibid., § 41) and United States (ibid., § 42).
[13] 20th International Conference of the Red Cross, Res. XXVIII (ibid., § 48).
[14] UN General Assembly, Res. 2444 (XXIII) (adopted by unanimous vote of 111 votes in favour to none against) (ibid., § 45).
[15] UN General Assembly, Res. 2675 (XXV) (adopted by 109 votes in favour, none against and 8 abstentions) ( ibid., § 46).
[16] ICTY, Kupreškić case, Judgment (ibid., §§ 49 and 132); Inter-American Commission on Human Rights, Case 11.137 (Argentina) (ibid., § 133).
[17] ICTY, Kupreškić case, Judgment (ibid., §§ 49 and 132).
[18] ICTY, Kupreškić case, Judgment (ibid., §§ 49 and 132).
[19] See, e.g., the practice of the ICRC (ibid., §§ 51, 53–61 and 135–142).
[20] See the practice of Algeria (ibid., § 147), Argentina (ibid., § 160), Australia (ibid., § 161), Belgium (ibid., § 148), Canada (ibid., §§ 149, 162 and 168), France (ibid., §150), Germany (ibid., §§ 151 and 169), India (ibid., § 170), Ireland (ibid., § 152), Italy (ibid., §§ 153 and 171), Netherlands (ibid., §§ 154, 163 and 172), New Zealand (ibid., § 164), Spain (ibid., § 155), Turkey (ibid., § 174), United Kingdom (ibid., § 157) and United States (ibid., § 175).
[21] Protocol II to the Convention on Certain Conventional Weapons, Article 3(4) (cited in Vol. II, Ch. 28, § 4); Protocol III to the Convention on Certain Conventional Weapons, Article 1(5) (cited in Vol. II, Ch. 30, § 109); Amended Protocol II to the Convention on Certain Conventional Weapons, Article 3(10) (cited in Vol. II, Ch. 28, § 4).
[22] Switzerland, Declaration made upon signature and reservation made upon ratification of Additional Protocol I (cited in Vol. II, Ch. 5, § 156).
[23] Switzerland, Statement at the Diplomatic Conference leading to the adoption of the Additional Protocols (ibid., § 173).
[24] Austria, Statement at the Diplomatic Conference leading to the adoption of the Additional Protocols (ibid., § 167).
[25] United Kingdom, Reservations and declarations made upon ratification of Additional Protocol I (ibid., § 158).
[26] See Ch. 4, footnote 33.
[27] See, e.g., the military manuals of Australia (cited in Vol. II, Ch. 5, § 185), Benin (ibid., § 186), Croatia (ibid., § 188), France (ibid., § 190), Italy (ibid., § 191), Madagascar (ibid., § 192), Nigeria (ibid., § 194), Spain (ibid., § 195), Sweden (ibid., § 196) and Togo (ibid., § 197).