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Interpretive Guidance on the Notion of Direct Participation in Hostilities under International Humanitarian Law

Adopted by the Assembly of the International Committee of the Red Cross on 26 February 2009

Published online by Cambridge University Press:  11 June 2009

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Abstract

The present document resulted from an expert process initiated and conducted by the ICRC from 2003 to 2008. Dr. Nils Melzer, Legal Adviser at the ICRC, who has been responsible for the expert process since 2004, is the author of the Interpretive Guidance and most background documents and expert meeting reports produced during the process. The ICRC would like to express its gratitude to the experts, all of whom participated in the process in their personal capacity.

Type
Reports and documents
Information
International Review of the Red Cross , Volume 90 , Issue 872: Direct participation in hostilities , December 2008 , pp. 991 - 1047
Copyright
Copyright © International Committee of the Red Cross 2009

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References

1 This is the full text of the ICRC's “Interpretive Guidance on the Notion of Direct Participation in Hostilities under International Humanitarian Law”. This text, along with all other materials produced in the expert process, such as reports, background documents, etc. will be available at www.icrc.org.

2 For more information on the expert process, see the document “Overview of the ICRC's Expert Process (2003–2008).”

3 See, e.g., Art. 5 [2] (c) and (g), Statutes of the International Red Cross and Red Crescent Movement.

4 For the purposes of this Interpretive Guidance, the phrases “direct participation in hostilities”, “taking a direct part in hostilities” and “directly participating in hostilities” will be used synonymously.

5 The status, rights, and protections of persons outside the conduct of hostilities does not depend on their qualification as civilians but on the precise personal scope of application of the provisions conferring the relevant status, rights, and protections (e.g., Art 4 GC III, Art 4 GC IV, common Article 3, Art 75 AP I and Arts 4 to 6 AP II).

6 For the sake of simplicity, when discussing the consequences of civilian direct participation in hostilities, the Interpretive Guidance will generally refer to loss of protection against “direct attacks”. Unless stated otherwise, this terminology includes also the suspension of civilian protection against other “dangers arising from military operations” (Arts 51 [1], [3] AP I and 13 [1], [3] AP II). This entails, for example, that civilians directly participating in hostilities may not only be directly attacked themselves, but also do not have to be taken into account in the proportionality assessment when military objectives in their proximity are attacked.

7 Arts 51 [3] AP I; 13 [3] AP II. See also Henckaerts/Doswald-Beck, Customary International Humanitarian Law, Volume I: Rules (Cambridge University Press, 2005), Rule 6 [hereafter: Customary IHL]. Regarding the terminology of “loss of protection against direct attacks” used in the Interpretive Guidance see above note 6.

8 For example, medical and religious personnel of the armed forces lose their protection in case of “hostile” or “harmful” acts outside their privileged function (Arts 21 GC I, 11 [2] AP II; Customary IHL, above note 7, Vol. I, Rule 25). Combatants hors de combat lose their protection if they commit a “hostile act” or “attempt to escape” (Art. 41 [2] AP I).

9 As of 1 November 2008, 168 States were party to AP I. At the same time, the ratification of GC I–IV was virtually universal (194 States parties).

10 Art. 50 [1] AP I. According to Customary IHL, above note 7, Vol. I, Rule 5, this definition of civilian reflects customary IHL in international armed conflict. The categories covered by Art. 4 A [1], [2] and [3] GC III are included in the general definition of armed forces under Art. 43 [1] AP I. See also Sandoz et al. (eds.), Commentary on the Additional Protocols of 8 June 1977 to the Geneva Conventions of 12 August 1949 (Geneva: ICRC, 1987), §1916 f. [hereafter: Commentary AP].

11 For example, Art. 22 [2] of the Brussels Declaration (1874) and Art. 29 H IV R (1907) refer to “civilians” in contradistinction to “soldiers”. Similarly, as their titles suggest, the Geneva Conventions (1949) use the generic category of “civilian persons” (GC IV) as complementary to members of the “armed forces” (GC I and GC II). Even though the scope of application of each convention does not exactly correspond to the generic categories mentioned in their respective titles, the categories of “civilian” and “armed forces” are clearly used as mutually exclusive in all four Conventions. For example, GC I, GC II and GC IV refer to “civilian” wounded, sick and shipwrecked (Art. 22 [5] GC I; Art. 35 [4] GC II; Arts 20, 21, 22 GC IV) as opposed to the generic categories protected by GC I and GC II, namely the wounded, sick and shipwrecked of the “armed forces” (titles GC I and GC II). Similarly, Art. 57 GC IV refers to “military” wounded and sick as opposed to the generic category protected by GC IV, namely “civilian persons”. Other provisions of the conventions also use the term “civilian” as opposed to “military” (Art. 30 [2] GC III: “military or civilian medical unit”; Art. 32 GC IV: “civilian or military agents”; Art. 144 [1] GC IV: “military and civil instruction”; Art. 93 [2] GC III: “civilian clothing”, presumably as opposed to military uniform; Arts 18, 19, 20, 57 GC IV: “civilian hospitals”, presumably as opposed to military hospitals; Art. 144 [2] GC IV: “civilian, military, police or other authorities”) or to “combatants and non-combatants” (Art. 15 GC IV). None of these instruments suggests the existence of additional categories of persons who would qualify neither as civilians, nor as members of the armed forces or as participants in a levée en masse.

12 Affirmative also Commentary AP (above note 10), § 1914. The ICTY defined the concept of civilians for situations of international armed conflict as “persons who are not, or no longer, members of the armed forces” (ICTY, Prosecutor v. Blaskic, Case No. IT-95-14-T, Judgment of 3 March 2000, § 180). For the relevant discussion during the expert meetings see: Report DPH 2005, pp. 43 f., 58, 74; Report DPH 2006, pp. 10, 12 f., 19 f.; Report DPH 2008, pp. 35, 37.

13 Art. 43 [1] AP I; Customary IHL, above note 7, Vol. I, Rule 4.

14 Art. 1 H IV R; Arts 13 [1], [2], [3] and [6] GC I and GC II; Art. 4 A [1], [2], [3] and [6] GC III.

15 In the ICRC's view, in international armed conflict, any person failing to qualify for prisoner-of-war status under Art. 4 GC III must be afforded the fundamental guarantees set out in Art. 75 AP I, which have attained customary nature and, subject to the nationality requirements of Art. 4 GC IV, also remains a “protected person” within the meaning of GC IV.

16 As illustrated by the treatment of spies (Arts 29–31 H IV R; Art. 46 AP I) and of other combatants failing to distinguish themselves as required by IHL (Art. 44 AP I), loss of entitlement to combatant privilege or prisoner-of-war status does not necessarily lead to loss of membership in the armed forces.

17 While the prevailing opinion during the 2006 expert meeting was supportive of this interpretation, some concerns were expressed that this approach could be misunderstood as creating a category of persons protected neither by GC III nor by GC IV (Report DPH 2006, pp. 15 f.). For the ICRC's position in this respect see, e.g., above note 15.

18 See Arts 13 [2] GC I and GC II and Art. 4 A [2] GC III.

19 See, e.g., Art. 3 H IV R; Art. 4 A [1] GC III; Art. 43 AP I.

20 Pictet (ed.), Commentary on the Third Geneva Convention Relative to the Treatment of Prisoners of War (Geneva: ICRC, 1960), p. 57 [hereafter: Commentary GC III].

21 See also Report DPH 2006, p. 16.

22 For the basic positions in this respect, see, most notably, ICJ, Military and Paramilitary Activities in and Against Nicaragua (Nicaragua v. United States of America), Judgment of 27 June 1986 (Merits), § 115; ICTY, Prosecutor v. Tadic, Case No. IT-94-A, Judgment of 15 July 1999 (Appeals Chamber), § 145; ICJ, Application of the Convention on the Prevention and Punishment of the Crime of Genocide (Bosnia and Herzegovina v. Serbia and Montenegro), Judgment of 27 February 2007, § 413; ILC, Report to the General Assembly on the work of its 53rd session (2001), UN Doc. A/56/10, Draft Article 8, Commentary § 5.

23 See also below note 26.

24 This was the prevailing opinion during the expert meetings (Report DPH 2006, pp. 16 ff.; Report DPH 2008, pp. 43 f.). For recent national case law reflecting this position, see: Israeli High Court of Justice, The Public Committee Against Torture et al. v. The Government of Israel et al., (HCJ 769/02), Judgment of 13 December 2006, § 26, where the Court held that, under IHL governing international armed conflict, independent Palestinian armed groups operating in a context of belligerent occupation necessarily qualified as civilians. With regard to the temporal scope of loss of protection for members of such groups, the Court nevertheless concluded that: “a civilian who has joined a terrorist organization which has become his ‘home’, and in the framework of his role in that organization he commits a chain of hostilities, with short periods of rest between them, loses his immunity from attack ‘for such time’ as he is committing the chain of acts. Indeed, regarding such a civilian, the rest between hostilities is nothing other than preparation for the next hostility” (ibid., § 39).

25 See also Report DPH 2006, pp. 16 ff., 52 f.; Report DPH 2008, pp. 43 f. For States party to Additional Protocol I, the law governing international armed conflicts also applies to armed conflicts between States and national liberation movements within the meaning of Article 1 [4] AP I.

26 According to Commentary GC III (above note 20), p. 57: “Resistance movements must be fighting on behalf of a ‘Party to the conflict’ in the sense of Art. 2, otherwise the provisions of Art. 3 relating to non-international conflicts are applicable, since such militias and volunteer corps are not entitled to style themselves a ‘Party to the conflict’ ”. The travaux préparatoires are silent on the possible parallel existence of international and non-international aspects within the greater context of the same armed conflict. For the relevant discussion during the expert meetings see Report DPH 2005, p. 10; Report DPH 2006, pp. 17 ff. and 53 f.; Report DPH 2008, pp. 43 f. It should be noted that “internal disturbances and tensions, such as riots, isolated and sporadic acts of violence and other acts of a similar nature” (Art. 1 [2] AP II) do not reach the threshold of “protracted armed violence”, which is required for the emergence of a separate non-international armed conflict (ICTY, Prosecutor v. Tadic, Case No. IT-94-1-AR72, Decision on the Defence Motion for Interlocutory Appeal on Jurisdiction of 2 October 1995, § 70).

27 See Section II below.

28 See Report DPH 2006, p. 16; Report DPH 2008, pp. 44, 49.

29 See Section II.3.(b) below and, with regard to private contractors, Section III.2.

30 Art. 2 H IV R; Art. 4 [6] GC III. See also the reference to Art. 4 [6] GC III in Art. 50 [1] AP I.

31 Art. 31 [1] Vienna Convention on the Law of Treaties.

32 See Customary IHL, above note 7, Vol. I, p. 19.

33 On the danger of extending the concept of direct participation in hostilities beyond specific acts, see also Section IV.2 below. During the expert meetings, the approach based on continuous direct participation in hostilities was criticized as blurring the distinction made by IHL between loss of protection based on conduct (civilians) and on status or function (members of armed forces or organized armed groups). See Background Doc. DPH 2004, p. 36; Background Doc. DPH 2005, WS IV–V, p. 10; Report DPH 2005, pp. 44, 48, 50. See also the discussions in Report DPH 2006, pp. 20 ff.; Report DPH 2008, pp. 46 ff.

34 Art. 3 GC I–IV (emphases added).

35 According to Commentary GC III (above note 20), p. 37: “Speaking generally, it must be recognized that the conflicts referred to in Art. 3 are armed conflicts, with ‘armed forces’ on either side engaged in ‘hostilities’ – conflicts, in short, which are in many respects similar to an international war …”.

36 According to Pictet (ed.), Commentary on the Fourth Geneva Convention Relative to the Protection of Civilian Persons in Time of War (Geneva: ICRC, 1958), p. 40: “Article 3 has an extremely wide field of application and covers members of the armed forces as well as persons who do not take part in the hostilities. In this instance, however, the Article naturally applies first and foremost to civilians – that is to people who do not bear arms” (emphasis added).

37 As of 1 November 2008, 164 States were party to AP II.

38 For the high threshold of application of Additional Protocol II, see Art. 1 [1] AP II.

39 Draft Art. 25 [1] AP II was adopted by consensus in the Third Committee on 4 April 1975 (O.R., Vol. XV, p. 320, CDDH/215/Rev.1). See also the ICRC's Commentary (October 1973) on the original version of Art. 25 [1] of the Draft of AP II submitted to the Diplomatic Conference of 1974–1977: “[…] sont considérés comme civils tous les êtres humains qui se trouvent sur le territoire d‘une Partie contractante où se déroule un conflit armé au sens de l'article premier et qui ne font pas partie des forces armées ou groupes armés” [emphasis added].

40 Art. 1 [1] AP II.

41 Art. 13 [1] and [3] AP I. This interpretation is further supported by the respective contexts in which the Protocol refers to “civilians” (Arts 13, 14, 17 AP II) and the “civilian population” (title Part IV AP II; Arts 5 [1] (b) and (e), 13, 14, 15, 17 and 18 AP II).

42 Affirmative ICTY, Prosecutor v. Martic, Case No. IT-95-11-A, Judgment of 8 October 2008, §§ 300–302. This was the prevailing view also during the expert meetings (see Report DPH 2005, pp. 43 f.; Report DPH 2006, pp. 20 ff.; Report DPH 2008, pp. 46 ff.).

43 Note that the concept of organized armed group is also used in IHL governing international armed conflict to describe organized armed actors other than the regular armed forces which operate under a command responsible to a party to the conflict and, therefore, qualify as part of the armed forces of that party (Art. 43 [1] AP I, see Section I above).

44 See the Commentary AP (above note 10), § 4462: “The term ‘armed forces’ of the High Contracting Party should be understood in the broadest sense. In fact, this term was chosen in preference to others suggested such as, for example, ‘regular armed forces’, in order to cover all the armed forces, including those not included in the definition of the army in the national legislation of some countries (national guard, customs, police forces or any other similar force)”, referring to O.R., Vol. X, p. 94, CDDH/I/238/Rev.1. On the potential qualification of police forces as part of the armed forces of a party to the conflict, see also the discussion in Report DPH 2005, p. 11; Report DPH 2006, pp. 43, 52 f.; Report DPH 2008, pp. 54, 64, 68.

45 According to Bothe et al., New Rules for Victims of Armed Conflicts: Commentary on the Two 1977 Protocols Additional to the Geneva Conventions of 1949 (The Hague: Martinus Nijhoff, 1982), p. 672, the terms “organized” and “under responsible command” in Art. 1 [1] AP II “inferentially […] recognize the essential conditions prescribed under art. 43 of Protocol I: that the armed force be linked to one of the parties to the conflict; that they be organized; and that they be under responsible command”.

46 See Section I.2.(c) above and Section II.3.(b) below.

47 See the Commentary AP (above note 10), § 4460.

48 Although Art. 1 AP II refers to armed conflicts “between” State armed forces and dissident armed forces or other organized armed groups, the actual parties to such a conflict are, of course, the High Contracting Party and the opposing non-State party, and not their respective armed forces.

49 Background Doc. DPH 2005, Armed Groups (IV–V), p. 15.

50 On the collective or individual nature of continuous combat function, see Report DPH 2008, pp. 55 ff.

51 On the qualification of conduct as direct participation in hostilities, see Section V below.

52 Combatant privilege, namely the right to directly participate in hostilities with immunity from domestic prosecution for lawful acts of war, is afforded only to members of the armed forces of parties to an international armed conflict (except medical and religious personnel), as well as to participants in a levée en masse (Arts 1 and 2 H IV R; Art. 43 [1] AP I). Although all privileged combatants have a right to directly participate in hostilities, they do not necessarily have a function requiring them to do so (e.g. cooks, administrative personnel). Conversely, individuals who assume continuous combat function outside the privileged categories of persons, as well as in non-international armed conflict, are not entitled to combatant privilege under IHL (see also Section X below).

53 During the expert meetings, the prevailing view was that persons cease to be civilians within the meaning of IHL for as long as they continuously assume a function involving direct participation in hostilities (“continuous combat function”) for an organized armed group belonging to a party to a non-international armed conflict (Expert Paper DPH 2004 (Prof. M. Bothe); Report DPH 2005, pp. 43 f., 48 ff., 53 ff., 63 ff., 82 f.; Report DPH 2006, pp. 9 ff., 20 ff., 29–32, 66 f.; Report DPH 2008, pp. 46–60).

54 See also Sections I.2.(c) and II.2.(b) above and, more generally, Section VII.2 below.

55 See Section III below.

56 Regarding the qualification of recruiting and training, financing and propaganda as direct participation in hostilities, see Sections V.2.(a) and (b); VI.1 below.

57 Regarding the qualification as direct participation in hostilities of purchasing, smuggling, transporting, manufacturing and maintaining of weapons, explosives and equipment, as well as of collecting and providing intelligence, see Sections V.1.(a); V.2.(a), (b) and (g); VI.1 below.

58 Obviously, such lack of “membership” does not exclude that civilian supporters of organized armed groups may incur criminal responsibility for their activities under national and, in the case of international crimes, also international law. See Section X below.

59 See also Report DPH 2006, pp. 25 ff.; Report DPH 2008, pp. 49–57.

60 See Section VIII below.

61 This trend led to an initiative by the Swiss government, in cooperation with the ICRC, to address the issue of private military and security companies. This initiative resulted in the ‘Montreux Document on Pertinent International Legal Obligations and Good Practices for States Related to Operations of Private Military and Security Companies During Armed Conflict’ of 17 September 2008, agreed upon by 17 participating States.

62 On the concept of civilian, see Sections I and II above. On the concept of direct participation in hostilities, see Sections IV to VI below.

63 See Report DPH 2005, pp. 74 f.

64 On the concept of continuous combat function, see Section II.3.(b) above.

65 Report DPH 2005, p. 80.

66 Report DPH 2006, pp. 34 f.

67 See Section VIII below.

68 Of the categories of persons entitled to prisoner-of-war status under Art. 4 [1] to [6] GC III, those described in Art. 4 [4] GC III (civilians accompanying the armed forces) and Art. 4 [5] GC III (civilian crew members of the merchant marine or civil aircraft) are civilians (Art. 50 [1] AP I). As any other civilians, they are excluded from the categories entitled to combatant privilege, namely members of the armed forces and participants in a levée en masse (Art. 43 [1] and [2], 50 [1] AP I; Arts 1 and 2 H IV R) and, therefore, do not have a right to directly participate in hostilities with immunity from domestic prosecution. See also Section X below, as well as the brief discussion in Report DPH 2006, pp. 35 f.

69 Report DPH 2005, p. 82.

70 On the concept of continuous combat function, see Section II.3.(b) above. On the subsidiary functional determination of membership specifically in international armed conflict, see Section I.3.(c) above.

71 The prevailing view expressed during the expert meetings was that, for the purposes of the conduct of hostilities, private contractors and employees authorized by a State to directly participate in hostilities on its behalf would cease to be civilians and become members of its armed forces under IHL, regardless of formal incorporation. It was noted that, from the historical letters of marque and reprisal issued to privateers to the modern combatant privilege, direct participation in hostilities with the authority of a State has always been regarded as legitimate and, as such, exempt from domestic prosecution. See Report DPH 2003, pp. 4 f.; Report DPH 2004, pp. 11 ff., 14; Expert Paper DPH 2004 (Prof. M. Schmitt), pp. 8 ff.; Report DPH 2005, pp. 74 ff. and 80 f.; Background Doc. DPH 2005, WS VIII-IX, p. 17.

72 See Report DPH 2005, pp. 81 f.

73 Ibid.

74 Art. 31 [1] Vienna Convention on the Law of Treaties.

75 The concept of hostilities is frequently used in treaties regulating situations of international and non-international armed conflict, for example in the following contexts: opening of hostilities, conduct of hostilities, acts of hostility, persons (not) taking part in hostilities, effects of hostilities, suspension of hostilities, end of hostilities. See Title and Art. 1 H III; Title Section II H IV R; Art. 3 [1] GC I–IV; Art. 17 GC I; Art. 33 GC II; Title Section II and Arts 21 [3], 67, 118 and 119 GC III; Arts 49 [2], 130, 133, 134 and 135 GC IV; Arts 33, 34, 40 and 43 [2], 45, 47, 51 [3], 59 and 60 AP I and Title Part IV, Section I AP I; Arts 4 and 13 [3] AP II; Arts 3 [1] – [3] and 4 ERW Protocol.

76 According to Art. 1 [2] AP II, such situations do not constitute armed conflicts.

77 In fact, armed conflict can arise without any occurrence of hostilities, namely through a declaration of war or the occupation of territory without armed resistance (Article 2 GC I–IV). Furthermore, considerable portions of IHL deal with issues other than the conduct of hostilities, most notably the exercise of power and authority over persons and territory in the hands of a party to the conflict. See also Report DPH 2005, pp. 13, 18 f.

78 See also Section VIII below. See further: Report DPH 2006, pp. 25 ff., 70 ff.

79 Report DPH 2005, p. 17; Background Doc. DPH 2005, WS II-III, p. 2.

80 See Art. 22 H IV R (Section II on “Hostilities”). Treaty law does not establish uniform terminology for the conduct of hostilities but refers, apart from “hostilities”, also to “warfare” (Title Part III, Section I and Art. 35 [1] AP I), “military operations” (Art. 53 GC IV; Art. 51 [1] AP I; Art. 13 [1] AP II), or simply “operations” (Art. 48 AP I).

81 See Arts 43 [2] AP I, 45 [1] and [3] AP I, 51 [3] AP I, 67 [1] (e) AP I and 13 [3] AP II.

82 Art. 3 GC I–IV.

83 Arts 51 [3] AP I and Arts 43 [2] AP I; 67 [1] (e) AP I and 13 [3] AP II.

84 This was the prevailing view also during the expert meetings (Report DPH 2005, p. 29; Report DPH 2006, p. 62). Affirming the synonymous meaning of the notions of “active” and “direct” participation in hostilities: ICTR, Prosecutor v. Akayesu, Case No. ICTR-96-4-T, Judgment of 2 September 1998, § 629. At first sight, it may appear that the Preparatory Committee for the Establishment of an International Criminal Court implied a distinction between the terms “active” and “direct” in the context of the recruitment of children when it explained that: “The words ‘using’ and ‘participate’ have been adopted in order to cover both direct participation in combat and also active participation in military activities linked to combat” (emphases added). Strictly speaking, however, the Committee made a distinction between “combat” and “military activities linked to combat”, not between “active” and “direct” participation.

85 This was the prevailing view also during the expert meetings (Background Doc. DPH 2004, p. 30; Report DPH 2004, pp. 15 ff.; Report DPH 2005, p. 13). Of course, this does not exclude that some of the consequences, particularly with regard to immunity from prosecution for having directly participated in hostilities, may be regulated differently for the various categories of persons involved in international and non-international armed conflicts.

86 See Arts 43 [2] AP I, 51 [3] AP I, 67 [1] (e) AP I and 13 [3] AP II.

87 This was the prevailing view also during the expert meetings (see Report DPH 2004, pp. 24 f.; Report DPH 2005, pp. 17–24; Report DPH 2006, pp. 37 f.; Report DPH 2008, pp. 33 ff.).

88 For purposes of this Interpretive Guidance, the notion of “hostile” act refers to a specific act qualifying as direct participation in hostilities. According to the Commentary AP (above note 10), § 1943: “It seems that the word ‘hostilities’ covers not only the time that the civilian actually makes use of a weapon, but also, for example, the time that he is carrying it, as well as situations in which he undertakes hostile acts without using a weapon”. Verri, Dictionary of the International Law of Armed Conflict (Geneva: ICRC, 1992), p. 57, defines hostilities as: “acts of violence by a belligerent against an enemy in order to put an end to his resistance and impose obedience”, and Salmon, Dictionnaire de droit international public (Bruxelles: Bruylant, 2001), p. 550 (hostilités): “Ensemble des actes offensifs ou défensifs et des opérations militaires accomplis par un belligérant dans le cadre d'un conflit armé” (all emphases added). See also the use of the term “hostile act” in Arts 41 [2] and 42 [2] AP I. On the meaning and interrelation of the notions of “hostilities” and “hostile acts” see further Report DPH 2004, pp. 24 f.; Report DPH 2005, pp. 17–24; Report DPH 2006, pp. 37 f.

89 Report DPH 2006, pp. 28 f.; Report DPH 2008, pp. 35–40. For a similar argument made in recent domestic case law, see: Israel HCJ, PCATI v. Israel, above note 24, § 39.

90 See also Section II.3 above. On the distinct temporal scopes of the loss of protection for organized armed actors and civilians see Section VII below.

91 Report DPH 2008, pp. 36–42.

92 This also was the prevailing view during the expert meetings (see Report DPH 2006, p. 38).

93 On the cumulative nature of these requirements, see also Report DPH 2006, pp. 40 f., 43 ff., 49 f.

94 Background Doc. DPH 2004, pp. 27 f.; Background Doc. DPH 2005, WS II-III, p. 6.

95 Background Doc. DPH 2004, p. 25; Report DPH 2005, p. 33.

96 The use of weapons or other means to commit acts of violence against human and material enemy forces is probably the most uncontroversial example of direct participation in hostilities (Customary IHL, above note 7, Vol. I, Rule 6, p. 22).

97 During the expert meetings, there was wide agreement that the causation of military harm as part of the hostilities did not necessarily presuppose the use of armed force or the causation of death, injury or destruction (Report DPH 2005, p. 14), but essentially included “all acts that adversely affect or aim to adversely affect the enemy's pursuance of its military objective or goal” (Report DPH 2005, pp. 22 f., 31). The concerns expressed by some experts that the criterion of “adversely affecting” military operations or military capacity was too wide and vague and could be misunderstood to authorize the killing of civilians without any military necessity are addressed below in Section IX (see Report DPH 2006, pp. 41 f.).

98 Report DPH 2005, pp. 11, 29.

99 The prevailing view during the expert meetings was that guarding captured military personnel was a clear case of direct participation in hostilities (Background Doc. DPH 2004, pp. 9; Report DPH 2005, pp. 15 f.). Nevertheless, to the extent practically possible, the guarding of captured military personnel as a means of preventing their liberation by the enemy should be distinguished from the exercise of administrative, judicial and disciplinary authority over them while in the power of a party to the conflict, including in case of riots or escapes, which are not part of a hostile military operation. This nuanced distinction was not discussed during the expert meetings. See also the discussion on “exercise of power or authority over persons or territory”, below notes 163–165 and accompanying text.

100 Report DPH 2005, p. 31.

101 CNA have been tentatively defined as “operations to disrupt, deny, degrade, or destroy information resident in computers and computer networks, or the computer and networks themselves” (Background Doc. DPH 2003, pp. 15 ff., with references) and may be conducted over long distances through radio waves or international communication networks. While they may not involve direct physical damage, the resulting system malfunctions can be devastating. CNE, namely “the ability to gain access to information hosted on information systems and the ability to make use of the system itself” (ibid., with references), though not of a direct destructive nature, could have equally significant military implications. During the expert meetings, CNA causing military harm to the adversary in a situation of armed conflict were clearly regarded as part of the hostilities (Report DPH 2005, p. 14).

102 See Report DPH 2005, p. 29.

103 During the expert meetings, the example was given of a civilian woman who repeatedly peeked into a building where troops had taken cover in order to indicate their position to the attacking enemy forces. The decisive criterion for the qualification of her conduct as direct participation in hostilities was held to be the importance of the transmitted information for the direct causation of harm and, thus, for the execution of a concrete military operation. See Report DPH 2004, p. 5.

104 During the expert meetings, it was held that the required threshold of harm would clearly be met where an act can reasonably be expected to cause material damage to objects or persons, namely death, injury or destruction (Report DPH 2005, pp. 30 f.; Background Doc. DPH 2004, pp. 5 f., 9 f., 28).

105 Accordingly, Section III of the Hague Regulations (entitled “Hostilities”) prohibits the “attack or bombardment, by whatever means, of towns, villages, dwellings, or buildings which are undefended” (Art. 25 H IV R).

106 Article 49 [1] AP I. Attacks within the meaning of IHL (Art. 49 [1] AP I) should not be confused with attacks as understood in the context of crimes against humanity (see below note 167), or with armed attacks within the meaning of the jus ad bellum, both of which are beyond the scope of this study.

107 On belligerent nexus, see Section V.3 below. For the relevant discussions on Draft Art. 44 AP I during the Diplomatic Conference of 1974–1977, see CDDH/III/SR.11, pp. 93 f.

108 Needless to say, such attacks are invariably prohibited under IHL governing both international and non-international armed conflict. See, for example, Arts 48 AP I, 51 AP I and 13 AP II; Customary IHL, above note 7, Vol. I, Rule 1.

109 For the qualification of sniping as an attack within the meaning of IHL, see, e.g. ICTY, Prosecutor v. Galic, Case No. IT-98-29-T, Judgment of 5 December 2003, § 27 in conjunction with § 52.

110 ICTY, Prosecutor v. Strugar, Case No. IT-01-42-T, Judgment of 31 January 2005, §§ 282 f. in conjunction with § 289.

111 Art. 35 [1] AP I.

112 Art. 22 H IV R (Section II on Hostilities).

113 According to the Commentary AP (above note 10), § 1679, “to restrict this concept [i.e. of “direct participation in hostilities”] to combat and to active military operations would be too narrow, while extending it to the entire war effort would be too broad, as in modern warfare the whole population participates in the war effort to some extent, albeit indirectly. The population cannot on this ground be considered to be combatants […]”. Similarly ibid., Commentary Art. 51 AP I, § 1945. Affirmative also ICTY, Prosecutor v. Strugar, Case No. IT-01-42-A, Judgment of 17 July 2008, §§ 175–176. See also the distinction between “taking part in hostilities” and “work of a military character” in Art. 15 [1] (b) GC IV. The position reflected in the Commentary corresponds to the prevailing opinion expressed during the expert meetings (Report DPH 2005, p. 21).

114 According to the Commentary AP (above note 10), § 1944, “[…] ‘direct’ participation means acts of war which by their nature or purpose are likely to cause actual harm to the personnel and equipment of the enemy armed forces”. Affirmative also ICTY, Prosecutor v. Strugar, Appeal, (above note 16), § 178. During the expert meetings, it was emphasized that “direct participation” in hostilities is neither synonymous with “involvement in” or “contribution to” hostilities, nor with “preparing” or “enabling” someone else to directly participate in hostilities, but essentially means that an individual is personally “taking part in the ongoing exercise of harming the enemy” (Report DPH 2004, p. 10) and personally carrying out hostile acts which are “part of” the hostilities (Report DPH 2005, pp. 21, 27, 30, 34).

115 According to the Commentary AP (above note 10), § 4787: “The term ‘direct participation in hostilities’ […] implies that there is a sufficient causal relationship between the act of participation and its immediate consequences”. See also Report DPH 2005, pp. 30, 34 ff.

116 Report DPH 2005, p. 28.

117 Background Doc. DPH 2004, p. 27; Report DPH 2005, pp. 28, 34.

118 See also Background Doc. DPH 2004, pp. 27 f.; Report DPH 2004, pp. 11, 25; Report DPH 2005, pp. 28, 34.

119 According to the Commentary AP (above note 10), § 1679: “Direct participation in hostilities implies a direct causal relationship between the activity engaged in and the harm done to the enemy at the time and the place where the activity takes place” (emphasis added).

120 Background Doc. DPH 2004, pp. 9 f.; Report DPH 2005, pp. 14 f.

121 Background Doc. DPH 2004, pp. 14 f.

122 Although, during the expert meetings, civilian scientists and weapons experts were generally regarded as protected against direct attack, some doubts were expressed as to whether this assessment could be upheld in extreme situations, namely where the expertise of a particular civilian was of very exceptional and potentially decisive value for the outcome of an armed conflict, such as the case of nuclear weapons experts during the Second World War (Report DPH 2006, pp. 48 f.).

123 During the expert meetings, there was general agreement that civilian workers in an ammunitions factory are merely building up the capacity of a party to a conflict to harm its adversary, but do not directly cause harm themselves. Therefore, unlike civilians actually using the produced ammunition to cause harm to the adversary, such factory workers cannot be regarded as directly participating in hostilities (see Report DPH 2003, p. 2; Report DPH 2004, pp. 6 f.; Report DPH 2005, pp. 15, 21, 28 f., 34, 38; Report DPH 2006, pp. 48 ff., 60; Report DPH 2008, p. 63). The experts remained divided, however, as to whether the construction of improvised explosive devices (IED) or missiles by non-State actors could in certain circumstances exceed mere capacity-building and, in contrast to industrial weapons production, could become a measure preparatory to a concrete military operation (see Report DPH 2006, pp. 48 f., 60).

124 On the example of a civilian driver of an ammunition truck, see Section V.2.(e) below.

125 Report DPH 2004, p. 10; Report DPH 2005, pp. 35 f. For dissenting views, see: Report DPH 2006, pp. 26, 65; Report DPH 2008, pp. 51, 53 ff.

126 See Sections V.2.(c) and VI.1 below.

127 For the discussion during the expert meetings on “but for”-causation (i.e. the harm in question would not occur “but for” the act), see Report DPH 2004, pp. 11, 25; Report DPH 2005, pp. 28, 34.

128 Report DPH 2005, p. 35.

129 Report DPH 2004, p. 5; Report DPH 2005, pp. 35 f.

130 Background Doc. DPH 2004, p. 13; Report DPH 2004, pp. 11, 25; Report DPH 2005, p. 31.

131 Report DPH 2005, pp. 28, 31. See also the example provided in note 103, which was described as the equivalent of a “fire control system”.

132 Report DPH 2004, p. 10; Report DPH 2005, pp. 33, 35 f.

133 Report DPH 2005, p. 35.

134 See Section V.1 above.

135 Background Doc. DPH 2004, p. 28; Report DPH 2006, p. 48. Similar reasoning was recently adopted in domestic jurisprudence with regard to “driving a vehicle containing two surface-to-air missiles in both temporal and spatial proximity to both ongoing combat operations” (U.S. Military Commission, USA v. Salim Ahmed Hamdan, 19 December 2007, p. 6) and “driving the ammunition to the place from which it will be used for the purposes of hostilities” (Israel HCJ, PCATI v. Israel, above note 24, § 35).

136 Report DPH 2006, p. 48.

137 See also Report DPH 2005, pp. 32 f. Although it was recognized during the expert meetings that a civilian driver of an ammunition truck may have to face the risk of being mistaken for a member of the armed forces, it was also widely agreed that any civilian known to be present in a military objective had to be taken into account in the proportionality equation, unless and for such time as he or she directly participated in hostilities (Report DPH 2006, pp. 72 f.).

138 This view was generally shared during the expert meetings (Report DPH 2006, pp. 44 ff.; Report DPH 2008, pp. 70 ff.).

139 During the expert meetings, this scenario was illustrated by the concrete example of a woman who shielded two fighters with her billowing robe, allowing them to shoot at their adversary from behind her (Report DPH 2004, pp. 6 f.).

140 See Art. 51 [5] (a) AP I and, for the customary nature of this rule in international and non-international armed conflict, Customary IHL, above note 7, Vol. I, Rule 14. For the relevant discussion during the expert meetings, see Report DPH 2004, pp. 6 f.; Report DPH 2006, pp. 44 ff.; Report DPH 2008, p. 70.

141 While there was general agreement during the expert meetings that involuntary human shields could not be regarded as directly participating in hostilities, the experts were unable to agree on the circumstances in which acting as a voluntary human shield would, or would not, amount to direct participation in hostilities. For an overview of the various positions, see Report DPH 2004, p. 6; Report DPH 2006, pp. 44 ff.; Report DPH 2008, pp. 70 ff.

142 See also Arts 51 [7] and [8] AP I, according to which any violation of the prohibition on using civilians as human shields does not release the attacker from his obligations with respect to the civilian population and individual civilians, including the obligation to take the required precautionary measures.

143 See Report DPH 2004, p. 7; Report DPH 2008, pp. 71 f.

144 See above Section IV.

145 See Art. 22 H IV R (Section II on “Hostilities”).

146 See, most notably, the definition of “attacks” as acts of violence “against the adversary … ” (Art. 49 [1] AP I). Report DPH 2005, pp. 22 f., 26, 40; Report DPH 2006, pp. 50 ff.

147 The requirement of belligerent nexus is conceived more narrowly than the general nexus requirement developed in the jurisprudence of the ICTY and the ICTR as a precondition for the qualification of an act as a war crime (see: ICTY, Prosecutor v. Kunarac et al., Case No. IT-96-23, Judgment of 12 June 2002 (Appeals Chamber), § 58; ICTR, Prosecutor v. Rutaganda, Case No. ICTR-96-3, Judgment of 26 May 2003 (Appeals Chamber), § 570). While the general nexus requirement refers to the relation between an act and a situation of armed conflict as a whole, the requirement of belligerent nexus refers to the relation between an act and the conduct of hostilities between the parties to an armed conflict. During the expert meetings, it was generally agreed that no conduct lacking a sufficient nexus to the hostilities could qualify as direct participation in such hostilities. See Report, DPH 2005, p. 25 and, more generally, Background Doc. DPH 2004, pp. 25 f.; Report DPH 2004, pp. 10, 25; Background Doc. DPH 2005, WS II-III, p. 8; Report DPH 2005, pp. 9 f., 22 ff., 27, 34.

148 Report DPH 2006, pp. 51 f.

149 The same applies, for example, to armed violence carried out by independent armed groups in international armed conflict (see also above notes 24–27 and accompanying text). During the expert meetings there was general agreement regarding the importance of distinguishing, in contexts of armed conflict, between law enforcement operations and the conduct of hostilities. See Report DPH 2005, pp. 10 f.; Report DPH 2006, pp. 52 f.; Report DPH 2008, p. 49, 54, 62 ff.

150 During the expert meetings, there was almost unanimous agreement that the subjective motives driving a civilian to carry out a specific act cannot be reliably determined during the conduct of military operations and, therefore, cannot serve as a clear and operable criterion for “split second” targeting decisions. See Report DPH 2005, pp. 9, 26, 34, 66 f.; Report DPH 2006, pp. 50 f.; Report DPH 2008, p. 66.

151 During the expert meetings, there was agreement that ‘hostile intent’ is not a term of IHL, but a technical term used in rules of engagement (ROE) drafted under national law. ROE constitute national command and control instruments designed to provide guidance to armed personnel as to their conduct in specific contexts. As such, ROE do not necessarily reflect the precise content of IHL and cannot be used to define the concept of direct participation in hostilities. For example, particular ROE may for political or operational reasons prohibit the use of lethal force in response to certain activities, even though they amount to direct participation in hostilities under IHL. Conversely, ROE may contain rules on the use of lethal force in individual self-defence against violent acts that do not amount to direct participation in hostilities. Therefore, it was generally regarded as unhelpful, confusing or even dangerous to refer to hostile intent for the purpose of defining direct participation in hostilities. See Report DPH 2005, p. 37.

152 Report DPH 2005, pp. 22 f., 26, 40; Report DPH 2006, pp. 50 f.

153 It should be noted, however, that civilians protected under the Fourth Geneva Convention may not be compelled to do work “directly related to the conduct of military operations” or to serve in the armed or auxiliary force of the enemy (Arts 40 [2] and 51 [1] GC IV), and that civilian medical and religious personnel may not be compelled to carry out tasks which are not compatible with their humanitarian mission (Art. 15 [3] AP I; Art. 9 [1] AP II).

154 Therefore, all parties to an armed conflict are obliged to do everything feasible to ensure that children below the age of 15 years do not directly participate in hostilities and, in particular, to refrain from recruiting them into their armed forces or organized armed groups (Arts 77 [2] AP I and 4 [3] (c) AP II; Customary IHL, above note 7, Vol. I, Rule 137). Of course, as soon as children regain protection against direct attack, they also regain the special protection afforded to children under IHL (Arts 77 [3] AP I and 4 [3] (d) AP II).

155 See also Report DPH 2005, pp. 9, 11.

156 Report DPH 2004, p. 25.

157 This was also the prevailing opinion during the expert meetings (see Report DPH 2003, p. 6; Background Doc. DPH 2004, pp. 14, 31 f.).

158 The use of force by individuals in defence of self or others is an issue distinct from the use of force by States in self-defence against an armed attack, which is governed by the jus ad bellum and is beyond the scope of this study.

159 E.g. Art. 4 GC IV.

160 E.g. Art. 5 GC III; Art. 75 [1] AP I.

161 On the belligerent nexus of civil unrest, see below note 169 and accompanying text.

162 Treaty IHL expressly confirms the law enforcement role, for example, of occupying powers (Art. 43 H IV R) and States party to a non-international armed conflict (Art. 3 [1] AP II).

163 E.g. Art. 42 GC III.

164 E.g. Arts 100–101 GC III.

165 See also above note 99 and accompanying text.

166 See, for example, Arts 3 GC I–IV; 32 GC IV and 75 [2] AP I. For the divergence of opinions expressed during the expert meetings on the qualification of hostage-taking as direct participation in hostilities, see Report DPH 2004, p. 4; Report DPH 2005, p. 11; Report DPH 2006, pp. 43 f.; Report DPH 2008, pp. 67 ff.

167 The concept of “attack” in the context of crimes against humanity does not necessarily denote conduct amounting to direct participation in hostilities under IHL. As explained by the ICTY “[t]he term ‘attack’ in the context of a crime against humanity carries a slightly different meaning than in the laws of war. [It] is not limited to the conduct of hostilities. It may also encompass situations of mistreatment of persons taking no active part in hostilities, such as someone in detention” (ICTY, Prosecutor v. Kunarac et al., Case No. IT-96-23, Judgment of 22 February 2001 (Trial Chamber), § 416 (emphasis added), confirmed by the Appeals Chamber in its Judgment in the same case of 12 June 2002, § 89). See also Report DPH 2006, pp. 42 f.

168 For the relevant discussion during the expert meetings, see Report DPH 2008, pp. 63–65.

169 See also Report DPH 2004, p. 4; Report DPH 2008, p. 67.

170 See also Report DPH 2004, p. 4; Report DPH 2005, pp. 8, 11.

171 With regard to the existence of a general nexus between civilian violence and the surrounding armed conflict, a similar conclusion was reached in ICTR, Prosecutor v. Rutaganda (above note 147), § 570.

172 Report DPH 2005, pp. 9 f., 22, 26, 28, 34, 40.

173 See Section VIII below.

174 The use of force in response to activities not fulfilling these requirements must be governed by the standards of law enforcement and of individual self-defence, taking into account the threat to be addressed and the nature of the surrounding circumstances.

175 See Section IX below.

176 See also the discussion in Report DPH 2006, pp. 54–63. On the temporal scope of the loss of protection, see Section VII below.

177 See also the related discussion on direct causation in collective operations, Section V.2 above. (c).

178 For the relevant discussions during the expert meetings, see: Background Doc. DPH 2004, pp. 7, 10, 13, 21; Background Doc. DPH 2005, WS VI–VII, p. 10; Report DPH 2005, p. 19; Report DPH 2006, pp. 56–63. Regarding the distinction of preparatory measures, deployments and withdrawals entailing loss of protection against direct attack from preparations, attempts and other forms of involvement entailing criminal responsibility, see Report DPH 2006, pp. 57 ff.

179 Art. 44 [3] AP I.

180 See above note 114 and accompanying text, as well as Section V.2.(b).

181 On the qualification of such activities as direct participation in hostilities see also Section V.2.(a)(b) above.

182 During the expert meetings, it was emphasized that the distinction between preparatory measures that do and, respectively, do not qualify as direct participation in hostilities should be made with utmost care so as to ensure that loss of civilian protection would not be triggered by acts too remote from the actual fighting. In order for the word “direct” in the phrase direct participation in hostilities to retain any meaning, civilians should be liable to direct attack exclusively during recognizable and proximate preparations, such as the loading of a gun, and during deployments in the framework of a specific military operation (Report DPH 2006, pp. 55, 60 f.).

183 See the Commentary AP (above note 10), §§ 1679, 1943, 4788, which recalls that several delegations to the Diplomatic Conference of 1974–1977 had indicated that the concept of hostilities included preparations for combat and return from combat. In their responses to the 2004 Questionnaire, a majority of experts considered that deployment to the geographic location of a hostile act should already qualify as direct participation in hostilities and, though more hesitant, tended towards the same conclusion with regard to the return from that location. See Background Doc. DPH 2004, pp. 7 (I, 1.3.), 10 (I, 2.4.), 13 (I, 3.4.), 20 (I, 6.4.). See also Report DPH 2005, pp. 65 f.

184 While this was also the prevailing opinion during the expert meetings (see Report DPH 2005, p. 66) some experts feared that the continued loss of protection after the execution of a specific hostile act invited arbitrary and unnecessary targeting (Report DPH 2006, pp. 56 f., 61 ff.).

185 See Report DPH 2005, p. 66, Report DPH 2006, p. 55.

186 Regarding the terminology of “loss of protection against direct attacks” used in the Interpretive Guidance see above note 6.

187 On the concept of continuous combat function, see Section II.3.(b) above.

188 On the applicability of the criterion of continuous combat function for the determination of membership in irregularly constituted militia, volunteer corps and resistance movements belonging to States, see Section I.3.(c) above.

189 Arts 51 [3] AP I and 13 [3] AP II; Customary IHL, above note 7, Vol. I, Rule 6. The customary nature of this rule was affirmed also in ICTY, Prosecutor v. Blaskic, Case No. IT-95-14-A, Judgment of 29 July 2004, § 157, with references to earlier case law. For recent domestic jurisprudence expressly accepting the customary nature of Art. 51 [3] AP I, including the phrase “for such time as”, see: Israel HCJ, PCATI v. Israel, above note 24, § 30.

190 On the beginning and end of direct participation in hostilities see Section VI above.

191 Regarding the practical impossibility of reliably predicting future conduct of a civilian, see also Report DPH 2006, pp. 66 ff.

192 According to the Commentary AP (above note 10), § 4789: “If a civilian participates directly in hostilities, it is clear that he will not enjoy any protection against attacks for as long as his participation lasts. Thereafter, as he no longer presents any danger for the adversary, he may not be attacked”. See also the description of direct participation in hostilities as potentially “intermittent and discontinuous” in ICTY, Prosecutor v. Strugar, Appeal, (above note 16), § 178. Although, during the expert meetings, the mechanism of the revolving door of protection gave rise to some controversy, the prevailing view was that, under the texts of Art. 3 [1] GC I–IV and the Additional Protocols, continuous loss of civilian protection could not be based on recurrent acts by individual civilians, but exclusively on the concept of membership in State armed forces or an organized armed group belonging to a non-State party to the conflict. See Report DPH 2004, pp. 22 f.; Report DPH 2005, pp. 63 f.; Report DPH 2006, pp. 64–68; Report DPH 2008, pp. 33–44.

193 On the mutual exclusivity of the concepts of civilian and organized armed group, see Section II.1 above. On the concept of continuous combat function, see Section II.3.(b) above.

194 Report DPH 2005, p. 49; Report DPH 2006, p. 65.

195 According to the Commentary AP (above note 10), § 4789: “Those who belong to armed forces or armed groups may be attacked at any time”. See also Expert Paper DPH 2004 (Prof. M. Bothe). Protection against direct attack is restored where members of armed groups fall hors de combat as a result of capture, surrender, wounds or any other cause (Art. 3 [1] GC I–IV. See also Art. 41 AP I.).

196 During the expert meetings, this widely supported compromise was described as a “functional membership approach”. For an overview of the discussions, see Report DPH 2003, p. 7; Background Doc. DPH 2004, pp. 34 ff.; Report DPH 2004, pp. 22 f.; Report DPH 2005, pp. 49, 59–65; 82 ff.; Report DPH 2006, pp. 29 ff., 65 f.

197 See Section II.3 above. See also Report DPH 2005, p. 59.

198 See also Section II.3 above. During the expert meetings, it was emphasized that the question of whether affirmative disengagement had taken place must be determined based on the concrete circumstances (Report DPH 2005, p. 63). On the precautions and presumptions to be observed in situations of doubt, see Section VIII below.

199 During the expert meetings, it was repeatedly pointed out that, while the revolving door of protection was part of the rule on civilian direct participation in hostilities expressed in Arts 51 [3] AP I and 13 [3] AP II, the practical distinction between members of organized armed groups and civilians was very difficult. During reactive operations carried out in response to an attack, the operating forces often lacked sufficient intelligence and had to rely on assumptions that were made based on individual conduct. Therefore, such operations would generally be restricted to the duration of the concrete hostile acts to which they responded. Conversely, proactive operations initiated by the armed forces based on solid intelligence regarding the function of a person within an organized armed group could also be carried out in a moment when the targeted persons were not directly participating in hostilities (see Report DPH 2006, pp. 56 f.)

200 Art. 57 [2] (a) (i) AP I. According to Customary IHL, above note 7, Vol. I, Rule 16, this rule has attained customary nature in both international and non-international armed conflict.

201 Art. 57 [2] (b) AP I. According to Customary IHL, above note 7, Vol. I, Rule 19, this rule has attained customary nature in both international and non-international armed conflict.

202 Report DPH 2006, p. 70 ff.

203 Arts 3 [4] CCW Protocol II (1980); 1 [5] CCW Protocol III (1980); 3 [10] CCW Amended Protocol II (1996). See also the French text of Art. 57 AP I (“faire tout ce qui est pratiquement possible”).

204 Apart from the determination as to whether a civilian is directly participating in hostilities, the principle of precaution in attack also requires that all feasible precautions be taken to avoid and in any event minimize incidental loss of civilian life, injury to civilians and damage to civilian objects. It also obliges those responsible to refrain from launching, to cancel or suspend attacks that are likely to result in incidental harm that would be “excessive” compared to the anticipated military advantage (see Art. 57 [2] (a) (ii); Art. 57 [2] (a) (iii) and Art. 57 [2] (b) AP I and, with regard to the customary nature of these rules in both international and non-international armed conflict, Customary IHL, above note 7, Vol. I, Rules 17, 18 and 19).

205 During the expert meetings, it was agreed that, in case of doubt as to whether a civilian constituted a legitimate military target, that civilian had to be presumed to be protected against direct attack (Report DPH 2005, pp. 44 f., 67 f.; Report DPH 2006, p. 70 ff.).

206 For situations of international armed conflict, this principle has been codified in Art. 50 [1] AP I. With regard to non-international armed conflicts, see also the Commentary AP (above note 10), § 4789, which states that, “in case of doubt regarding the status of an individual, he is presumed to be a civilian”.

207 See also Report DPH 2005, pp. 11 f.

208 Article 22 H IV R. See also Article 35 [1] AP I: “In any armed conflict, the right of the Parties to the conflict to choose methods and means of warfare is not unlimited”.

209 See also Report DPH 2006, p. 76; Report DPH 2008, pp. 24, 29 ff.

210 See, for example, the prohibitions or restrictions imposed on the use of poison (Art. 23 [1] (a) H IV R; 1925 Geneva Protocol prohibiting asphyxiating, poisonous or other gases and analogous liquids, materials or devices), expanding bullets (1899 Hague Declaration IV/3) and certain other weapons (CCW-Convention and Protocols of 1980, 1995 and 1996, Ottawa Convention on Anti-Personnel Mines of 1997, Convention on Cluster Munitions of 2008), as well as the prohibition of methods involving the denial of quarter (Art. 40 AP I; Art. 23 [1] (d) H IV R) and the resort to treachery or perfidy (Art. 23 [1] (b) H IV R; Art. 37 AP I). See also Report DPH 2006, p. 76; Report DPH 2008, pp. 18 f.

211 Article 49 [1] AP I.

212 During the expert meetings, Section IX.2. of the Interpretive Guidance remained highly controversial. While one group of experts held that the use of lethal force against persons not entitled to protection against direct attack is permissible only where capture is not possible, another group of experts insisted that, under IHL, there is no legal obligation to capture rather than kill. Throughout the discussions, however, it was neither claimed that there was an obligation to assume increased risks in order to protect the life of an adversary not entitled to protection against direct attack, nor that such a person could lawfully be killed in a situation where there manifestly is no military necessity to do so. For an overview of the relevant discussions see Report DPH 2004, pp. 17 ff.; Report DPH 2005, pp. 31 f., 44. ff., 50, 56 f., 67; Report DPH 2006, pp. 74–79; Report DPH 2008, pp. 7–32.

213 See, most notably: Commentary AP (above note 10), § 1389.

214 Report DPH 2008, pp. 7 f., 19 f. See also the statement of Lauterpacht that “the law on these subjects [i.e. on the conduct of hostilities] must be shaped – so far as it can be shaped at all – by reference not to existing law but to more compelling considerations of humanity, of the survival of civilization, and of the sanctity of the individual human being” (cited in: Commentary AP (above note 10), § 1394).

215 United Kingdom: Ministry of Defence, The Manual of the Law of Armed Conflict (Oxford: OUP, 2004), Section 2.2 (Military Necessity). Similar interpretations are provided in numerous other contemporary military manuals and glossaries. See, for example, NATO: Glossary of Terms and Definitions (AAP-6V), p. 2-M-5; United States: Department of the Army, Field Manual 27-10 (1956), § 3; US Department of the Navy, The Commander's Handbook on the Law of Naval Operations, NWP 1–14M/MCWP 5–12-1/COMDTPUB P5800.7A (2007), § 5.3.1, p. 5–2; France: Ministry of Defence, Manuel de Droit des Conflits Armés (2001), pp. 86 f.; Germany: Federal Ministry of Defense, Triservice Manual ZDv 15/2: Humanitarian Law in Armed Conflicts (August 1992) § 130; Switzerland: Swiss Army, Regulations 51.007/IV, Bases légales du comportement à l'engagement (2005), § 160. Historically, the modern concept of military necessity has been strongly influenced by the definition provided in Art. 14 of the “Lieber Code” (United States: Adjutant General's Office, General Orders No. 100, 24 April 1863).

216 United Kingdom, Manual of the Law of Armed Conflict (above note 215), Section 2.4 (Humanity). Although no longer in force, see also the formulation provided in: United States: Department of the Air Force, Air Force Pamphlet, AFP 110–31 (1976), § 1–3 (2), p. 1–6. Thus, as far as they aim to limit death, injury or destruction to what is actually necessary for legitimate military purposes, the principles of military necessity and of humanity do not oppose, but mutually reinforce, each other. Only once military action can reasonably be regarded as necessary for the accomplishment of a legitimate military purpose, do the principles of military necessity and humanity become opposing considerations that must be balanced against each other as expressed in the specific provisions of IHL.

217 See Commentary AP (above note 10), § 1395. See also the determination of the International Court of Justice that the prohibition on the use of means and methods of warfare of a nature to cause unnecessary suffering to combatants constitutes an intransgressible principle of international customary law and a cardinal principle of IHL, which outlaws the causation of “harm greater than that unavoidable to achieve legitimate military objectives”. See ICJ, Advisory Opinion on the Legality of the Threat or Use of Nuclear Weapons, 8 July 1996, § 78.

218 See also the Declaration of St Petersburg (1868), which states: “That the only legitimate object which States should endeavour to accomplish during war is to weaken the military forces of the enemy; That for this purpose it is sufficient to disable [authentic French version: mettre hors de combat] the greatest possible number of men”.

219 It has long been recognized that matters not expressly regulated in treaty IHL should not, “for want of a written provision, be left to the arbitrary judgment of the military commanders” (Preamble H II; Preamble H IV) but that, in the words of the famous Martens Clause, “civilians and combatants remain under the protection and authority of the principles of international law derived from established custom, from the principles of humanity and from the dictates of public conscience” (Art. 1 [2] AP I). First adopted in the Preamble of Hague Convention II (1899) and reaffirmed in subsequent treaties and jurisprudence for more than a century, the Martens Clause continues to serve as a constant reminder that, in situations of armed conflict, a particular conduct is not necessarily lawful simply because it is not expressly prohibited or otherwise regulated in treaty law. See, e.g., Preambles H IV R (1907), AP II (1977), CCW (1980); Arts 63 GC I, 62 GC II, 142 GC III and 158 GC IV (1949); ICJ, Nuclear Weapons AO (above note 217), § 78; ICTY, Prosecutor v. Kupreskic et al., Case No. IT-95-16-T-14, Judgment of January 2000, § 525). For the discussion on the Martens Clause during the expert meetings, see Report DPH 2008, pp. 22 f.).

220 For recent national case law reflecting this position see: Israel HCJ, PCATI v. Israel, above note 24, § 40, where the Court held that “a civilian taking a direct part in hostilities cannot be attacked at such time as he is doing so, if a less harmful means can be employed. […] Arrest, investigation, and trial are not means which can always be used. At times the possibility does not exist whatsoever; at times it involves a risk so great to the lives of the soldiers, that it is not required […]. It might actually be particularly practical under the conditions of belligerent occupation, in which the army controls the area in which the operation takes place, and in which arrest, investigation, and trial are at times realizable possibilities […]. Of course, given the circumstances of a certain case, that possibility might not exist. At times, its harm to nearby innocent civilians might be greater than that caused by refraining from it. In that state of affairs, it should not be used”.

221 It is in this sense that Pictet's famous statement should be understood that “[i]f we can put a soldier out of action by capturing him, we should not wound him; if we can obtain the same result by wounding him, we must not kill him. If there are two means to achieve the same military advantage, we must choose the one which causes the lesser evil”. See Pictet, Development and Principles of International Humanitarian Law (Dordrecht, Nijhoff 1985), pp. 75 f. During the expert meetings, it was generally recognized that the approach proposed by Pictet is unlikely to be operable in classic battlefield situations involving large-scale confrontations (Report DPH 2006, pp. 75 f., 78) and that armed forces operating in situations of armed conflict, even if equipped with sophisticated weaponry and means of observation, may not always have the means or the opportunity to capture rather than kill (Report DPH 2006, p. 63).

222 According to Art. 51 [1] AP I the rule expressed in Art. 51 [3] AP I is “additional to other applicable rules of international law”. Similarly, Art. 49 [4] AP I recalls that the provisions of Section I AP I (Arts 48–67) are “additional to the rules concerning humanitarian protection contained […] in other international agreements binding upon the High Contracting Parties, as well as to other rules of international law relating to the protection of civilians […] against the effects of hostilities”. While these provisions refer primarily to sources of IHL other than AP I itself, they also aim to include “instruments of more general applicability that continue to apply wholly or partially in a situation of armed conflict” (see the Commentary AP (above note 10), §§ 128–131), such as “the regional and universal Conventions and Covenants relating to the protection of human rights” (ibid., Commentary Art. 49 AP I, § 1901) and other applicable treaties, which “can have a positive influence on the fate of the civilian population in time of armed conflict” (ibid., Commentary Art. 51 [1] AP I, § 1937). During the expert meetings, some experts suggested that the arguments made in Section IX should be based on the human right to life. The prevailing view was, however, that the Interpretive Guidance should not examine the impact of human rights law on the kind and degree of force permissible under IHL. Instead, a general savings clause should clarify that the text of the Interpretive Guidance was drafted without prejudice to the applicability of other legal norms, such as human rights law (Report DPH 2006, pp. 78 f.; Report DPH 2008, p. 21 f.).

223 Art. 43 [2] AP I (except medical and religious personnel); Arts 1 and 2 H IV R.

224 Conversely, combatant privilege provides no immunity from prosecution under international or national criminal law for violations of IHL.

225 This was also the prevailing view during the expert meetings (see Report DPH 2006, p. 81). The experts also agreed that the legality or illegality of an act under national or international law is irrelevant for its qualification as direct participation in hostilities (Background Doc. DPH 2004, p. 26; Report DPH 2004, p. 17; Report DPH 2005, p. 9; Report DPH 2006, p. 50).

226 Neither the statutes of the Military Tribunals that followed the Second World War (i.e. the International Military Tribunal in Nuremberg and the International Military Tribunal for the Far East in Tokyo), nor the current statutes of the ICTY, the ICTR, the ICC and the SCSL penalize civilian direct participation in hostilities as such.

227 The Martens Clause (above note 219) expresses a compromise formulated after the States participating in the 1899 Peace Conferences had been unable to agree that civilians taking up arms against an established occupying power should be treated as privileged combatants or as franc-tireurs subject to execution. Since then, States have successively extended the combatant privilege to participants in a levée en masse, militias and volunteer corps (H IV R, 1907), organized resistance movements (GC I-III, 1949) and certain national liberation movements (AP I, 1977). As far as civilians are concerned, however, IHL still neither prohibits their direct participation in hostilities, nor affords them immunity from domestic prosecution.

228 Obviously, where Additional Protocol I is applicable, members of the armed forces of national liberation movements within the meaning of Article 1 [4] AP I would benefit from combatant privilege and, thus, from immunity against prosecution for lawful acts of war, even though the movements to which they belong are non-State parties to an armed conflict.

229 See also Background Doc. DPH 2004, p. 26; Report DPH 2004, p. 17; Report DPH 2005, p. 9; Report DPH 2006, pp. 80 f.

230 See above note 226.

231 For the nexus criterion as established by the ICTY and the ICTR see, most notably, ICTY, Prosecutor v Tadic, Interlocutory Appeal (above note 26), §§ 67, 70; ICTY, Prosecutor v. Kunarac et al. (above note 147), §§ 55 ff.; ICTR, Prosecutor v. Rutaganda (above note 147), §§ 569 f.

232 Arts 23 [1] (b) H IV R and 37 [1] AP I (international armed conflict). For the customary nature of this rule in non-international armed conflict, see Customary IHL, above note 7, Vol. I, Rule 65. Under the ICC Statute, the treacherous killing or wounding of “individuals belonging to the hostile nation or army” (international armed conflict: Art. 8 [2] (b) (xi)) or of a “combatant adversary” (non-international armed conflict: Art. 8 [2] (e) (ix)) is a war crime.