1 Military and Paramilitary Activities in and against Nicaragua (Nicaragua v. United States of America), Judgment of 27 June 1986, [1986] ICJ Rep. 1 (hereinafter Nicaragua case), at 14 ff.

2 United States Diplomatic and Consular Staff in Teheran (United States of America v. Iran), Judgment of 24 May 1980, [1980] ICJ Rep. 1 (hereinafter Teheran Hostages case), at 3 ff.

3 The Prosecutor v. Dusko Tadić a/k/a ‘Dule’, Judgement (Appeals Chamber), Case No. IT-94-1-A, 15 July 1999 (hereinafter Tadić Appeals Chamber case).

4 Application of the Convention on the Prevention and Punishment of the Crime of Genocide (Bosnia and Herzegovina v. Serbia and Montenegro), Judgment of 26 February 2007 (hereinafter Bosnia v. Serbia case).

5 Ibid., para. 376; 1948 Convention on the Prevention and Punishment of the Crime of Genocide, 78 UNTS 277 (hereinafter Genocide Convention).

6 The claim was originally brought against the Federal Republic of Yugoslavia (FRY), later for reasons of state successions the respondent changed with effect from 4 February 2003 to Serbia and Montenegro and with effect from 3 June 2006 to the Republic of Serbia. Bosnia v. Serbia case, supra note 4, para. 1.

7 UN Doc. A/RES/56/83 (2001), also found at (2002) 62 Zeitschrift für ausländisches öffentliches Recht und Völkerrecht/Heidelberg Journal of International Law 797, Annex. See for a general introduction Tams, C. J., ‘All's Well that Ends Well – Comments on the ILC's Articles on State Responsibility’, (2002) 62 Zeitschrift für ausländisches öffentliches Recht und Völkerrecht/Heidelberg Journal of International Law 759Google Scholar.

8 A. Cassese, International Law (2005), 244. The ILC Articles profited from the input of many excellent legal academics and jurists including as far as the ICJ is concerned Judge Simma, who served on the ILC from 1997 to 2002 and in 1998 as chairman of the drafting committee concerned with state responsibility, Judge Al-Khasawneh (1987–99), Judge Bennouna (1987–98), Judge Tomka (1999–2002, in 2001 chairman of the drafting committee), and Judge Sepúlveda Amor (1997–2005), all of whom served in the ILC during the final phase of deliberations on state responsibility.

9 See Condorelli, L., ‘L'imputation à l'état d'un fait internationalement illicite: solutions classiques et nouvelles tendances’, (1984/VI) 189 Recueil des Cours 19Google Scholar; C. Kress, ‘L'organe de facto en droit international public – réflexions sur l'imputation à l'état de l'acte d'un particulier à la lumière des développements récents’, (2001) 105 RGDIP 93.

10 Certain Questions Relating to Settlers of German Origin in the Territory Ceded by Germany to Poland, Advisory Opinion, (1923) PCIJ Series B, No. 6, at 22; R. Jennings and A. Watts, Oppenheim's International Law, vol. I: Peace (1992), 540, para. 159; Bin Cheng, General Principles of Law as applied by International Courts and Tribunals (1987), 183; Starke, J. G., ‘Imputability in International Delinquencies’, (1938) 19 British Yearbook of International Law 105Google Scholar.

11 Questions of attribution may also arise concerning other subject matter of international law. The 1969 Vienna Convention on the Law of Treaties, (1969) 1155 UNTS 331, provides for rules which determine under which circumstances an expression of consent to be bound by a treaty can be attributed to a state. Here other considerations are of relevance than the field of state responsibility: see J. Griebel, Die Zurechnungskategorie der de facto-Organe im Recht der Staatenverantwortlichkeit (2004), 10 ff.

12 Here the Court in the Teheran Hostages case, supra note 2, para. 56, stated as follows, ‘The principal facts material to the Court's decision on the merits of the present case have been set out earlier in this judgment. Those facts have to be looked at by the Court from two points of view. First, it must determine how far, legally, the acts in question may be regarded as imputable to the Iranian State. Secondly, it must consider their compatibility or incompatibility with the obligations of Iran under treaties in force or under any other rule of international law that may be applicable’. See also Commentaries to the ILC Articles on Responsibility of States for internationally wrongful acts, UN Doc. A/56/10, (2001) Yearbook of the International Law Commission, vol. 2 (part 2) (hereinafter ILC Commentaries), at 81, para. 4. That the ICJ in the Bosnia v. Serbia case proceeded differently, first addressing the question of the genocide and only afterwards the attribution matter, shall not be of further concern for this paper. Obviously, the Court considered it to be important to seize the moment and elaborate on the various legal requirements of the prohibited forms of genocide. Considering the outcome of the case and the negative answer given to the attribution question this would not have been the case if attribution had been addressed first. And there may also have been considerations of practicability, considering that against the background of quite broad claims the relevant acts had to be identified before the question of attribution was addressed.

13 Griebel, supra note 11, at 156 ff. and at 163 ff.; S. Hobe and O. Kimminich, Einführung in das Völkerrecht (2004), at 235 ff.

14 Ago, R., ‘Third Report on State Responsibility’, (1971) Yearbook of the International Law Commission, vol. 2 (part 1), at 202, para. 15Google Scholar; Combacau, J. and Alland, D., ‘Primary and Secondary Rules in the Law of State Responsibility – Categorizing International Obligations’, (1985) 16 New York Journal of International Law 81Google Scholar; Annacker, C., ‘Part Two of the International Law Commission's Draft Articles on State Responsibility’, (1994) 37 German Yearbook of International Law 209Google Scholar; Condorelli, supra note 9, at 21; K. Ipsen, Völkerrecht (1999), at 536.

15 Arangio-Ruiz, G., ‘Preliminary Report on State Responsibility’, (1988) Yearbook of the International Law Commission, vol. 2 (part 1), at 10Google Scholar; Arangio-Ruiz, G., ‘Third Report on State Responsibility’, 1991 Yearbook of the International Law Commission, vol. 2 (part 1), at 7 paras. 1 ff.Google Scholar; Annacker, supra note 14, at 234 ff.

16 See ILC Articles, Arts. 31 and 34–9.

17 See ILC Articles, Art. 49.

18 W. Riphagen, Preliminary Report on State Responsibility, (1980) Yearbook of the International Law Commission, vol. 2 (part 1), at 112.

19 See ‘Affaire concernant l'accord relatif aux services aériens’, 18 RIAA, at 438 para. 81; Gabčíkovo-Nagymaros Project (Hungary v. Slovakia), Judgment, [1997] ICJ Rep. 1, at 7 and 55.

20 Griebel, supra note 11, at 17 ff.

21 Bosnia v. Serbia case, supra note 4, paras. 297 and 376.

22 Ibid., para. 390: the Republika Srpska and its military forces (Vojska Republike Srpske, VRS), the ‘Scorpions’, ‘Red Berets’, ‘Tigers’, and ‘White Eagles’.

23 Ibid., para. 384.

24 Ibid., paras. 385–389; Article 4 of the ILC Articles, entitled ‘Conduct of organs of a State’, reads as follows: ‘1. The conduct of any State organ shall be considered an act of that State under international law, whether the organ exercises legislative, executive, judicial or any other functions, whatever position it holds in the organization of the State, and whatever its character as an organ of the central Government or of a territorial unit of the State. 2. An organ includes any person or entity which has that status in accordance with the internal law of the State.’

25 Bosnia v. Serbia case, supra note 4, paras. 386–389.

26 Ibid., paras. 390–395.

27 Ibid., para. 391.

28 Ibid., para. 392.

29 Ibid., paras. 394 ff.

30 Ibid., para. 394.

31 Ibid., para. 397; Article 8 of the ILC Articles, entitled ‘Conduct directed or controlled by a State’, reads as follows: ‘The conduct of a person or group of persons shall be considered an act of a State under international law if the person or group of persons is in fact acting on the instructions of, or under the direction or control of, that State in carrying out the conduct.’

32 Bosnia v. Serbia case, supra note 4, para. 405 (annotation added).

33 Ibid., para. 406.

34 Ibid., para. 413.

35 While the Bosnia v. Serbia case was discussed by a couple of other commentators, these laid emphasis on other important aspects of the judgment. See Gill, T. D., ‘The “Genocide” Case: Reflections on the ICJ's Decision in Bosnia and Herzegovina v. Serbia’, (2007) 2 Hague Justice Journal 46Google Scholar; A. Cassese, ‘The Nicaragua and Tadić Test Revisited in Light of the ICJ Judgment on Genocide in Bosnia’, (2007) 18 EJIL 631; R. J. Goldstone and R. J. Hamilton, ‘Bosnia v. Serbia: Lessons from the International Court of Justice's Encounter with the International Criminal Tribunal for the Former Yugoslavia’, (2008) 21 LJIL 95; M. Milanović, ‘State Responsibility for Genocide: A Follow-up’, (2007) 18 EJIL 669; Sandesh Sivakumaran, ‘Application of the Convention of the Prevention and Punishment of the Crime of Genocide (Bosnia and Herzegovina v. Serbia and Montenegro)’, (2007) 56 ICLQ 695; Oellers-Frahm, K., ‘IGH: Bosnien-Herzegovina gegen Jugoslawien’, (2007) 4 Vereinte Nationen 165Google Scholar.

36 Bosnia v. Serbia case, supra note 4, para. 397 (annotation and emphasis added).

37 See for the ILC's understanding notes 38 and 39infra.

38 ILC Commentaries, supra note 12, Art. 4 at 84, para. 2, Art. 8 at 103 ff.; see for the drafting history of the ILC Articles, as well as for references to the relevant documents, M. Spinedi and B. Simma, United Nations Codification of State Responsibility (1987).

39 Ago, R., ‘Third Report on State Responsibility’, (1971) Yearbook of the International Law Commission, vol. 2 (part 1), para. 191Google Scholar. The rule of Art. 8(a) of the 1996 Draft Articles goes back to Roberto Ago, who from 1962 until 1979, when he became a judge at the ICJ, was the Special Rapporteur regarding state responsibility. His work concerning Part One of the Draft Articles on State Responsibility was left unchanged by his later successors Willem Riphagen and Gaetano Arangio-Ruiz; see Griebel, supra note 11, at 49 ff.

40 Many publications were dedicated specifically to this topic, inter alia Kress, supra note 9, at 93 ff.; Condorelli, supra note 9, at 19 ff.; Villalpando, S., ‘Attribution of Conduct to the State – How the Rules of State Responsibility May Be Applied within the WTO Dispute Settlement System’, (2002) 5 Journal of International Economic Law 393CrossRefGoogle Scholar; de Hoogh, A., ‘Articles 4 and 8 of the 2001 ILC Articles on State Responsibility; The Tadić Case and Attribution of Acts of Bosnian Serb Authorities to the Federal Republic of Yugoslavia’, (2001) 72 British Yearbook of International Law 255CrossRefGoogle Scholar; M. Plücken, ‘Probleme einer völkerrechtlichen Verantwortlichkeit von Staaten für Handlungen Privater’, B. Schöbener (ed.), Junge Rechtswissenschaft – Völker- und Europarecht (2008), 113 at 127; Griebel, supra note 11.

41 R. Higgins, Problems and Process – International Law and How We Use It (1994), 150; Ipsen, supra note 14, at 636 and 640 ff.; Kress, supra note 9, at 99; M. Shaw, International Law (2003), 704; Hobe and Kimminich, supra note 13, at 243; Villalpando, supra note 40, at 410; de Hoogh, supra note 40, at 277 ff.; M. Milanović, ‘State Responsibility for Genocide’, (2006) 17 EJIL 553.

42 Declaration on Principles of International Law Concerning Friendly Relations and Cooperation among States in Accordance with the Charter of the United Nations, UN Doc. A/RES/2625 (1970).

43 Ibid.

44 See supra section 2.

45 Nicaragua case, supra note 1, para. 20.

46 Ibid., para. 292.

47 Teheran Hostages case, supra note 2, paras. 57 ff. and 69 ff.

48 Ibid.

49 While there are discussions whether it is also possible for private groups to commit armed attacks, the question of attribution has certainly not lost its relevance; see Griebel, supra note 11, at 184 ff.

50 In this context one would have to take into account Art. 3(g) of the Definition of Aggression, UN Doc. A/RES/3314 (XXIX) (1974).

51 A. Randelzhofer in B. Simma, The Charter of the United Nations – A Commentary (2002), I, Art. 51, para. 42.

52 Supra section 2.

53 See G. Dahm, J. Delbrück, and R. Wolfrum, Völkerrecht, (2002) I/3, at 890 ff., 912 n. 54.

54 Decision of the Trial Chamber in the Prosecuter v. Dusko Tadić a/k/a ‘Dule’, Judgement of 7 May 1997 (Trial Chamber), Case No. IT-94-1-T (hereinafter Tadić Trial Chamber case), at 288 (Judge McDonald, Separate and Dissenting Opinion).

55 See Milanović, supra note 41, at 576.

56 Ibid.

57 Bosnia v. Serbia case, supra note 4, para. 391.

58 Nicaragua case, supra note 1, para. 109.

59 See, e.g., Milanović, supra note 41, at 576.

60 Nicaragua case, supra note 1, para. 277.

61 Tadić Trial Chamber case, supra note 54, para. 585.

62 Tadić Appeals Chamber case, supra note 3, para. 112.

63 Ibid., paras. 115 ff..

64 Ibid., paras. 120 and 131 ff..

65 ILC Commentaries, supra note 12, at 105 ff.; see also Cassese, supra note 35, at 663.

66 Ibid.

67 J. O'Brien, International Law (2001), 370; Cassese, supra note 8, at 249; Villalpando, supra note 40, at 411; Higgins, supra note 41, at 155; Plücken, supra note 40, at 135; Hobe and Kimminich, supra note 13, 243 ff.

68 Griebel, supra note 11, at 94 ff.; Tadić Trial Chamber case, supra note 54, para. 585; Kress also seems to regard the elaborations within paras. 108–115 of the Nicaragua case as a single test of effective control, supra note 9, at 104 ff.

69 McDonald, supra note 54, at 299; see also Milanović, supra note 41, at 579.

70 ILC Commentaries, supra note 12, at 84, para. 3, at 91 para. 7; see also Griebel, supra note 11, at 37.

71 Milanović, supra note 41, at 579, 602.

72 This is true unless the rather exceptional case is given where the state is responsible although the act was ultra vires: see ILC Articles, Art. 7.

73 ILC Commentaries, supra note 12, at 90 para. 11.

74 Ibid.

75 Ibid., with instructive examples.

76 De Hoogh, supra note 40, at 268.

77 The notion ‘de facto organ’ is mostly used to denounce persons acting under Art. 8 ILC Articles; see Ago, supra note 39, para. 191; Kress, supra note 9, at 96, 101; Cassese, supra note 8, at 247; Villalpando, supra note 40, at 410 ff..

78 Bosnia v. Serbia case, supra note 4, para. 397.

79 For the purposes of this article it is of no greater relevance that Art. 8 ILC Articles also speaks of ‘direction’ as a further applicable test. Considering the drafting history of Art. 8 ILC Articles and the ILC Commentaries, it unfortunately remains unclear what the content of ‘direction’ is; see Griebel, supra note 11, at 69 ff., 74 ff..

80 See supra notes 66 and 67.

81 McDonald, supra note 54, at 295 ff.; Milanović, supra note 41, at 576 ff..

82 See in particular Bosnia v. Serbia case, supra note 4, paras. 399 ff..

83 Although judgments of the ICJ are only binding inter partes, the Court in principle tries to follow its earlier judgments.

84 See for these ILC Commentaries, supra note 12, at 104 n. 161; Griebel, supra note 11, at 167 ff.

85 Teheran Hostages case, supra note 2, at 29, para. 58.

86 Ibid., paras. 58 ff.

87 Bosnia v. Serbia case, supra note 4, para. 392.

88 See, e.g., Riphagen, W., ‘Seventh Report on State Responsibility’, (1986) Yearbook of the International Law Commission, vol. 2 (part 1), at 11, para. 6Google Scholar; Tadić Appeals Chamber case, supra note 3, para. 117; D. Blumenwitz, ‘Das universelle Gewaltanwendungsverbot und die Bekämpfung des grenzüberschreitenden Terrorismus’, (1986) Bayerische Verwaltungsblätter 739.

89 Griebel, supra note 11, at 169.

90 Nicaragua case, supra note 1, para. 115 (emphasis added).

91 Ibid.

92 There is a certain dispute whether the control must be exercised concerning the operation or a specific action. While the Court in the Nicaragua case focused on control over the operation in the course of which the act is committed, the ILC adopted an even more restrictive approach, focusing on control over the act itself; see Griebel, supra note 11, at 172.

93 Ibid., at 172; see for a similar understanding Kress, supra note 9, at 105.

94 Armed Activities on the Territory of the Congo (Democratic Republic of the Congo v. Uganda), Judgment of 19 December 2005.

95 Ibid., para. 160.

96 Ibid., para. 161.

97 Although the ILC in its Commentaries on Art. 8 ILC Articles did not explicitly rely on the Teheran Hostages case, it is the same test as that embodied in Art. 8.

98 See for the evolution of the rule laid down in Art. 8 ILC Articles Griebel, supra note 11, at 47 ff..

99 Statement of the Chairman of the Drafting Committee B. Simma, International Law Commission, 13 August 1998, at 7. See also B. Simma, ‘The Work of the International Law Commission at its Fiftieth Session (1998), (1998) 67 Nordic Journal of International Law 452. At that time Judges Al-Khasawneh, Bennouna, and Sepúlveda Amor were also members of the ILC; see (1998) Yearbook of the International Law Commission, vol. 2 (part 2), at 13.

100 Bosnia v. Serbia case, supra note 4, para. 403 ff.; Griebel, supra note 11, at 170 ff.; see for a different view Cassese, supra note 35, at 655 ff..

101 Milanović, supra note 41, at 577; Griebel, supra note 11, at 179.

102 See for a short summary of the new views on this question Griebel supra note 11, at 147 ff.; see also Milanović, supra note 41, at 583 ff..

103 Bosnia v. Serbia case, supra note 4, para. 406.

104 See for the concept of intertemporal law Shaw, supra note 41, at 429 ff.; I. Brownlie, Principles of Public International Law (2003), 124 ff.; A. D'Amato, ‘International Law, Intertemporal Problems’, in R. Bernhardt (ed.), Encyclopedia of Public International Law (1995), II, at 1234 ff.

105 See supra note 7.

106 M. D. Evans, International Law (2006), at 587; Higgins, supra note 41, at 202; Shaw, supra note 41, at 1005.

107 Bosnia v. Serbia case, supra note 4, para. 393.

108 Ibid., para. 401.

109 Cassese, supra note 35, at 654.

110 Nicaragua case, supra note 1, para. 94.

111 Griebel, supra note 11, at 229.

112 Ibid., at 178 ff.; Plücken, supra note 40, at 148.

113 As indicated above, the authors are not of the opinion that there is a conflict, as one may regard the two tests as applicable in a different context; however, this might be seen differently from the perspective of the ICTY, see supra section 4.3; see in this respect Goldstone and Hamilton, supra note 35, in particular at 99–103.

114 See supra note 8.

115 Application of the Convention on the Prevention and Punishment of the Crime of Genocide (Croatia v. Serbia and Montenegro).

116 Higgins, supra note 41, at 146.