1 According to the 1978 Vienna Convention on Succession of States in Respect of Treaties 1946 UNTS 3 [hereinafter ‘Convention’], state succession is defined as ‘the replacement of one State by another in the responsibility for the international relations of territory’ (Art. 2(1)(b)).

2 Cahier, P., ‘Quelques aspects de la Convention de 1978 sur la succession d’États en matière de traités’, in Dutoit, B. and Grisel, E. (eds.), Mélanges Georges Perrin (1984)Google Scholar, at 76; Degan, V., ‘La succession d’États en matière de traités et les États nouveaux (issus de l’ex-Yougoslavie)’, (1996) 42 AFDI, at 213CrossRefGoogle Scholar; O’Connell, D. P., ‘Reflections on the State Succession Convention’, (1979) 39 (4)ZaöRV 725Google Scholar, at 726; A. Gruber, Le droit international de la succession d’États (1986), 89; I. Sinclair, ‘Some Reflections on the Vienna Convention on Succession of States in Respect of Treaties’, in Essays in Honour of Erik Castren (1978), 181; Caggiano, P., ‘The ILC Draft on the Succession of States in Respect of Treaties: A Critical Appraisal’, (1975) 1 Italian YIL 75Google Scholar, at 82–3; M. Craven, The Decolonization of International Law: State Succession and the Law of Treaties (2007), 16. See also O’Connell, D. P., ‘Recent Problems of State Succession in Relation to New States’, (1970) 130 RCADI, at 102Google Scholar. For arguments defending the Convention, see Szafarz, R., ‘Succession of States in Respect of Treaties in Contemporary International Law’, (1983) 12 Polish Y.B. Int’l L. 119Google Scholar, at 131–9.

3 O’Connell, supra note 2, at 726 (‘State succession is a subject altogether unsuited to the processes of codification’).

4 Mullerson, R., ‘Law and Politics in Succession of States: International Law on Succession of States’, in Burdeau, G. and Stern, B. (eds.), Dissolution, continuation et succession en Europe de l’Est (1994), 16–17Google Scholar; Caggiano, supra note 2, 71–72.

5 B. Stern, ‘Rapport de synthèse’, in G. Burdeau and B. Stern (eds.), supra note 4, at 385.

6 Report of the International Law Commission on the Work of its Twenty-Sixth Session, 6 May to 26 July 1974, UN Doc. A/9610/Rev.1 (1974), 169–70 [Polish Y.B. Int’l L, hereinafter ‘ILC Report, Twenty-Sixth Session, 1974’].

7 Szafarz, R., ‘Vienna Convention on Succession of States in Respect of Treaties: a General Analysis’, (1979–1980) 10 Polish Y.B. Int’l L. 77Google Scholar, at 107–8.

8 Ibid., 108; Caggiano, supra note 2, at 71.

9 It should be noted at the outset that the present article does not aim to examine a number of specific types of bilateral treaties (such as those establishing boundaries, creating territorial regimes, so-called ‘political’ or ‘personal’ treaties, etc.). Specific solutions prevail under the Convention for these treaties.

10 Under Art. 2 of the Convention the term ‘other State party’ ‘means in relation to a successor State any party, other than the predecessor State, to a treaty in force at the date of a succession of States in respect of the territory to which that succession of States relates’.

11 International Law Association (ILA), Conclusions of the Committee on Aspects of the Law of State Succession, Resolution no. 3/2008 (2008), adopted at the 73^rd Conference of the ILA, at point no. 6.

12 Recent articles include: P. Dumberry, ‘An Uncharted Question of State Succession: Are New States Automatically Bound by the BITs Concluded by Predecessor States Before Independence?’ (2015) Journal of International Dispute Settlement (forthcoming); A. Genest, ‘Sudan Bilateral Investment Treaties and South Sudan: Musings on State Succession to Bilateral Treaties in the Wake of Yugoslavia's Breakup’, (2014) TDM 3; Qerimi, Q. and Krasniqi, S., ‘Theories and Practice of State Succession to Bilateral Treaties: The Recent Experience of Kosovo’, (2013) 14 German Law Journal 1639Google Scholar. Much older studies on succession to bilateral treaties include, Keith, K. J., ‘Succession to Bilateral Treaties by Seceding States’, (1967) 61 AJIL 521CrossRefGoogle Scholar; A. P. Lester, ‘State Succession to Treaties in the Commonwealth’, (1963) ICLQ, 475. It should be noted that a number of articles have examined the question of bilateral treaties between two specific states: Koskenniemi, M. and Lehto, M., ‘La succession d’États dans l’ex-URSS, en ce qui concerne particulièrement les relations avec la Finlande’, (1992) 38 AFDI 179CrossRefGoogle Scholar; Hafner, G. and Kornfeind, E., ‘The Recent Austrian Practice of State Succession: Does the Clean Slate Still Exist?’, (1996) Austrian RIEL 1Google Scholar.

13 For a recent study on the work of the ILC regarding state succession to multilateral treaties, see Craven, supra note 2.

14 First Report on Succession of States and Governments in Respect of Treaties, prepared by the Special Rapporteur, Sir Humphrey Waldock, UN Doc. A/CN.4/202 (1968).

15 Second Report on Succession in Respect of Treaties, prepared by the Special Rapporteur, Sir Humphrey Waldock, UN Doc. A/CN.4/214 and Adds.1 & 2 (1969).

16 Third Report on Succession in Respect of Treaties, prepared by the Special Rapporteur, Sir Humphrey Waldock, UN Doc. A/CN.4/224 and Add.1 (1970).

17 Fourth Report on Succession in Respect of Treaties, prepared by the Special Rapporteur, Sir Humphrey Waldock, UN Doc. A/CN.4/249 (1971).

18 Fifth Report on Succession in Respect of Treaties, prepared by the Special Rapporteur, Sir Humphrey Waldock, UN Doc. A/CN.4/256 and Adds.1–4 (1972).

19 Draft Articles on Succession in Respect of Treaties: General Article Submitted by the Special Rapporteur as a Possible Means of Covering the Question of Lawfulness, UN Doc. A/CN.4/L.184 (1972).

20 Report of the International Law Commission on the Work of its Twenty-Fourth Session, 2 May to 7 July 1972, UN Doc. A/8710/Rev.1 (1972) [hereinafter ‘ILC Report, Twenty-Fourth Session, 1972’].

21 First Report on Succession of States in Respect of Treaties, Prepared by the Special Rapporteur, Sir Francis Vallat, UN Doc. A/CN.4/278 and Adds.1–6 (1974).

22 ILC Report, Twenty-Sixth Session, 1974, supra note 6.

23 This article will not examine the regime under the Convention for ‘Unification of States’ (Arts. 31 to 33) and cession of territory (Art. 15).

24 On the evolution of the work of the ILC, see Craven, supra note 2, at 131–2, 159–71.

25 It should be added that there are two other different scenarios which may result from the extinction of the predecessor state: unification of states and incorporation (or ‘absorption’) of a state.

26 In the case of the cession or transfer of territory the event affecting the territorial integrity of the predecessor state will result not in the creation of a new state but in the enlargement of the territory of an existing state.

27 Convention, supra note 1; 1983 Vienna Convention on Succession of States in Respect of State Property, Archives and Debts 22 ILM (1983), 306. It should be added that the Commentary to the Draft Articles on Nationality of Natural Persons in Relation to the Succession of States, adopted by the ILC on second reading in 1999, UN Doc. A/54/10 (1999), Ch. IV, paras. 44 and 45, in 1997 YILC, Vol. II, 13, at 41, paras. 1 and 3, while recognizing the theoretical distinction between Newly Independent States and ‘separation of part or parts of the territory’ (i.e. secession), does not include different provisions for the former.

28 Declaration of Principles of International Law Concerning Friendly Relations and Co-Operation Among States in Accordance with the Charter of the United Nations, UN Doc. A/RES/25/2625 (1970).

29 Some writers do not view Newly Independent States as a distinct category: Degan, V.-D., ‘Création et Disparition de l’État (à La Lumière du Démembrement de Trois Fédérations Multiethniques en Europe)’, (1999) 279 RCADI 195Google Scholar, at 298–9. See also Restatement (Third), Foreign Relations Law of the United States (1987),Vol. I, § 210, Reporters’ Notes No. 4, at 113.

30 Makonnen, Y., ‘State Succession in Africa: Selected Problems’, (1986/V) 200 RCADI 93, at 130–1Google Scholar; Bedjaoui, M., ‘Problèmes récents de succession d’Etats dans les Etats nouveaux’, (1970/II) 130 RCADI 455Google Scholar, at 468–9, 530. This point is discussed in: Z. Meriboute, La codification de la succession d’États aux Traités: Décolonisation, Sécession, Unification (1984), 29–30, 49, 56, 63.

31 ILC Report, Twenty-Sixth Session, 1974, supra note 6, at 236.

32 Ibid.

33 Ibid., at 212. See also M. K. Yasseen, ‘La Convention de Vienne sur la Succession d’Etats en matière de Traités’, (1978) 24 AFDI 59, 105; Szafarz, supra note 7, at 88; Menon, P. K., ‘The Newly Independent States and Succession in Respect of Treaties’, (1990) 18 Korean Journal of Comparative Law, at 145Google Scholar.

34 Szafarz, supra note 7, at 88–9; Menon, supra note 33, at 145.

35 Art. 17, Convention, supra note 1. See also ILC Report, Twenty-Sixth Session, 1974, supra note 6, at 236.

36 Art. 17(2), Convention, supra note 1. Para. 3 also provides an exception to this principle.

37 On this question, see the analysis of A. Di Stefano, ‘Article 24’, in G. Distephano and G. Gaggioli (eds.), Commentaire à la Convention de Vienne sur la succession d’États en matière de traités (2015 expected).

38 The full text of Art. 24(1) reads as follows: ‘A bilateral treaty which at the date of a succession of States was in force in respect of the territory to which the succession of States relates is considered as being in force between a newly independent State and the other State party when:

(a) they expressly so agree; or

(b) by reason of their conduct they are to be considered as having so agreed.’

39 The scopes of the two exceptions are discussed in Di Stefano, supra note 37, para. 35 ff.

40 Meriboute, supra note 30, at 73–8; Di Stefano, supra note 37, para. 19

41 See, ILC Report, Twenty-Sixth Session, 1974, supra note 6, at 187, 183, 188, 192–9, 240, 246.

42 Art. 34(2) Convention, supra note 1.

43 See the discussion in Dumberry, P. and Turp, D., ‘State Succession With Respect to Multilateral Treaties in the Context of Secession: From the Principle of Tabula Rasa to the Emergence of a Presumption of Continuity of Treaties’, (2013) 13 Baltic Yearbook of International Law 27CrossRefGoogle Scholar; V. Mikulka, ‘Article 34’ in G. Distephano and G. Gaggioli, supra note 37, para. 8ff.

44 Meriboute, supra note 30, at 216–17.

45 ILC Report, Twenty-Sixth Session, 1974, supra note 6, at 263, 266. See also Meriboute, supra note 30, at 156–7.

46 ILC Report, Twenty-Sixth Session, 1974, supra note 6, at 265.

47 Ibid.

48 Ibid.

49 R. D. Kearney, ‘The Twenty-Sixth Session of the International Law Commission’, (1975) 69 AJIL 591, at 600.

50 ILC Report, Twenty-Sixth Session, 1974, supra note 6, at 265.

51 Ibid., at 266.

52 Ibid.

53 R. J. Zedalis, ‘An Independent Quebec: State Succession to NAFTA’, (1996) 2(4) NAFTA: Law and Business Review of the Americas 3, at 9; Cahier, supra note 2, at 75–76.

54 ILC Report, Twenty-Fourth Session, 1972, supra note 20, at 296–7; ILC Report, Twenty-Sixth Session, 1974, supra note 6, at 265.

55 See United Nations Conference on Succession of States in Respect of Treaties, Vienna, 31 July–23 August 1978, Summary records of the plenary meetings and of the meetings of the Committee of the Whole Nations Unies, A/CONF.80/16/Add. 1 (1979), Vol. II, at 53–73, 107–14; Szafarz, supra note 7, at 103; Meriboute, supra note 30, at 159–61, 163; Cahier, supra note 2, at 76.

56 United Nations Conference on Succession of States in Respect of Treaties, supra note 55, at 114 (see also, at 53 et seq.). See also Zedalis, supra note 53, at 11–13; Mikulka, supra note 43, para. 40ff.

57 Yasseen, supra note 33, at 103.

58 Meriboute, supra note 30, at 216; O’Connell, supra note 2, at 164–78; Cahier, supra note 2, at 75; M. Maloney, ‘State Succession in Respect of Treaties: The Vienna Convention of 1978’, (1978–79) 19 VaJIL 913; J. Klabbers et al. (dirs.), Pilot Project on Documentation concerning State Practice relating to State Succession and Recognition (1999), 117; Szafarz, supra note 7, at 104; Caggiano, supra note 2, at 75.

59 Szafarz, supra note 7, at 104–5; Meriboute, supra note 30, at 162; Cahier, supra note 2, at 76; Mullerson, supra note 4, at 34; I. Brownlie, Principles of Public International Law (1998), 663–64; Restatement (Third), supra note 29, §210, ‘Reporters’ Notes’ no. 4, at 113; S. A. Williams, ‘International Legal Effects of Secession by Quebec’, (1992) York University Centre for Public Law and Public Policy, at 33; Majzub, D. B., ‘Does Secession Mean Succession? The International Law of Treaty Succession and an Independent Quebec’, (1998) 24 Queen's Law Journal 411Google Scholar, at 429.

60 Application of the Convention on the Prevention and Punishment of the Crime of Genocide (Bosnia and Herzegovinia v. Serbia and Montenegro), Preliminary Objections, [1996] ICJ Rep. 595, at 779. See also Caggiano, supra note 2, at 76; Szafarz, supra note 7, at 104–5, 108.

61 The application of the two exceptions set out at Art. 34(2) will be examined later.

62 ILC Report, Twenty-Sixth Session, 1974, supra note 6, at 211.

63 G. Abi-Saab, ‘The Newly Independent States and the Rules of International Law: An Outline’, (1962) 8 Howard L.J. 95, at 118.

64 Ibid., at 100.

65 Makonnen, supra note 30, at 129. See also Bedjaoui, supra note 30, at 490.

66 Makonnen, supra note 30, at 129.

67 Bedjaoui, supra note 30, at 469, 530.

68 Makonnen, supra note 30, at 129–30

69 Makonen, supra note 30, at 131.

70 Bedjaoui, supra note 30, at 493.

71 Szafarz, supra note 2, at 110.

72 Ibid.

73 Bedjaoui, supra note 30, at 526.

74 Yasseen, supra note 33, at 105, see also at 106.

75 ILC Report, Twenty-Sixth Session, 1974, supra note 6, at 169; Menon, supra note 33, at 145, 172.

76 ILC Report, Twenty-Sixth Session, 1974, supra note 6, at 211. It also mentioned that in ‘some categories of treaties, it is true, continuity in one form or another occurs with impressive regularity’ (at 237). See Succession of States in Respect of Bilateral Treaties: Second and Third Studies Prepared by the Secretariat, UN Doc. A/CN.4/243 and Add.l (1971), at 111ff.

77 Di Stefano, supra note 37, para. 14; Meriboute, supra note 30, at 78; Menon, supra note 33, at 145; Szafarz, supra note 7, at 97. For an earlier study supporting the principle of tabula rasa, see Lester, supra note 12, at 476–7, 506–7.

78 Di Stefano, supra note 37, paras. 14, 56, 76; Szafarz, supra note 2, at 130.

79 Keith, supra note 13, at 545.

80 ILA, Report of the 52^nd Conference, Helsinki (1966), 557–96; ILA, Report of the 53^rd Conference, Buenos Aires (1969), 589–633.

81 Third Report on Succession in Respect of Treaties, supra note 16, at 37. See also Craven, supra note 2, at 142ff.

82 Third Report on Succession in Respect of Treaties, supra note 16, at 39. See also ILC Report, Twenty-Sixth Session, 1974, supra note 6, at 237.

83 ILC Report, Twenty-Sixth Session, 1974, supra note 6, at 237 (see also at 169). On this question, see Szafarz, supra note 2, at 119–20.

84 ILC Report, Twenty-Sixth Session, 1974, supra note 6, at 212 (emphasis in the original). See also at 237.

85 This principle is reflected at Art. 24 of the Convention stating that the principle of tabula rasa applies to bilateral treaties unless the other state party to the original treaty has expressly (or tacitly) agreed to the continuation of that treaty.

86 ILC Report, Twenty-Sixth Session, 1974, supra note 6, at 239 (emphasis added). See also Gruber, supra note 2, at 182.

87 ILC Report, Twenty-Sixth Session, 1974, supra note 6, at 237.

88 Ibid.

89 Meriboute, supra note 30, at 79.

90 ILC Report, Twenty-Sixth Session, 1974, supra note 6, at 237.

91 Ibid.

92 Yasseen, supra note 33, at 108.

93 ILC Report, Twenty-Sixth Session, 1974, supra note 6, at 238 (emphasis in the original).

94 Cahier, supra note 2, at 72; Meriboute, supra note 30, at 74, 78; Yasseen, supra note 33, at 108; Menon, supra note 33, at 156; Szafarz, supra note 7, at 97.

95 ILC Report, Twenty-Sixth Session, 1974, supra note 6, at 237 (emphasis in the original).

96 Gruber, supra note 2, at 181.

97 It is surprising that the Convention's section dealing specifically with Newly Independent States (Arts. 24 to 26) does not contain a provision equivalent to Art. 35.

98 ILC Report, Twenty-Sixth Session, 1974, supra note 6, at 241; Gruber, supra note 2, at 181.

99 Art. 25, Convention, supra note 1.

100 ILC Report, Twenty-Sixth Session, 1974, supra note 6, at 237. See also Menon, supra note 33, at 161; Gruber, supra note 2, at 181; Meriboute, supra note 30, at 74; G. Bartolini, ‘Article 25’, in Distephano and Gaggioli (eds.), supra note 37, para. 15.

101 Thus, in Waldock's Third and Fourth Reports of 1970 and 1971 the general expression ‘new States’ was used for all states. See, for instance, Art. 13 entitled ‘The Position of new States in regard to Bilateral Treaties’ in Fourth Report on Succession in Respect of Treaties, supra note 17, at 145; Third Report on Succession in Respect of Treaties, supra note 16. See the discussion in Craven, supra note 2, at 131–2.

102 ILC Report, Twenty-Fourth Session, 1972, supra note 20, at 227.

103 Ibid., at 250.

104 Fourth Report on Succession in Respect of Treaties, supra note 17, at 145–6.

105 ILC Report, Twenty-Fourth Session, 1972, supra note 20, at 272–3.

106 ILC Report, Twenty-Sixth Session, 1974, supra note 6, at 239.

107 Art. 34(2)(b), Convention, supra note 2.

108 ILC Report, Twenty-Sixth Session, 1974, supra note 6, at 210. See also Yasseen, supra note 33, at 82.

109 ILC Report, Twenty-Sixth Session, 1974, supra note 6, at 210.

110 Eisemann, P. M., ‘Rapport du Directeur de la section de langue française du Centre’, in Eisemann, P. M. and Koskenniemi, M. (eds.), State Succession: Codification Tested Against the Facts (2000), 51, 53CrossRefGoogle Scholar; Stern, B., ‘La succession d’États’ (1996) 262 RCADI, at 314Google Scholar; Mikulka, supra note 43, para. 71.

111 Eisemann, supra note 110, at 53. Contra, ILA, supra note 11, no. 8 (‘The rebus sic stantibus rule is sometimes invoked as a way to obtain the renegotiation of the treaty’).

112 Stern, supra note 110, at 316.

113 ILA, New Delhi Conference 2002 – Committee on Aspects of The Law of State Succession - Rapport Final sur la Succession en matière de traités (2002), 11; Mikulka, supra note 43, para. 124.

114 Klabbers et al., supra note 58, Report by the Czech Republic, at 469, ad. no. 3; Mikulka, supra note 43, para. 71.

115 Hafner, G., ‘Austria and Slovenia: Succession to Bilateral Treaties and the State Treaty of 1955’, in Mrak, M. (ed.), State Succession (1999), 136Google Scholar.

116 The author is very grateful to Prof. Caroline Fournet (Groningen University, The Netherlands) for her insightful comments and remarks on this question. See also Shaw, M. N. and Fournet, C., ‘Article 62 – Changement Fondamental de Circonstances’, in Corten, O. and Klein, P. (eds.), Les conventions de Vienne sur le droit des traités – Commentaire article par article (2006)Google Scholar, Vol. III, at 2256, arguing that a succession of states should not be considered as a ‘fundamental change of circumstances’ in the context of the application of Art. 62 of the Vienna Convention on the Law of Treaties.

117 Sanum Investments Limited v. Government of the Lao People's Democratic Republic, UNCITRAL Arbitration Rules, PCA Case No. 2013–13, Award on Jurisdiction, 13 December 2013, para. 246: (‘the Tribunal considers that it would be excessive to say that all bilateral treaties are so personal, so related to intuitu personae questions that they cannot survive a State's succession. In other words, the Tribunal considers that it is necessary to consider the application of the general rule to bilateral treaties on a case-by-case basis.’ (emphasis in the original)). On the question of State succession to bilateral investment treaties, see Dumberry, supra note 12.

118 The Sanum tribunal answered the question in the affirmative (in the context of cession of territory): ‘It can indeed be the case that when a treaty is concluded between two States with planned economies, the extension of such treaty to a capitalist economy would fundamentally change the conditions for its application if the treaty was based on features specific to a planned economy and irreconcilable with the liberal principles of a capitalist economy.’ (Ibid., paras. 247–8). Yet, the tribunal ultimately held that the extension of the China–Laos Bilateral Investment Treaty to Macao would not radically change the condition of operation of the treaty.

119 See, for instance, M. Shaw, International Law (2008), 967; Craven, supra note 2, at 142; Menon, supra note 33, at 156ff; Stern, supra note 110, at 315; Di Stefano, supra note 37, para. 15; A. Goncalves Pereira, La succession d’États en matière de traités (1969), 149; O. Udokang, Succession of the New States to International Treaties (1972), 501; Zemanek, K., ‘State Succession after Decolonization’, (1965) 116 RCADI, at 238Google Scholar; Cahier, supra note 2, at 72; Meriboute, supra note 30, at 74, Yasseen, supra note 33, at 108.

120 ILA, supra note 11.

121 Mikulka, supra note 43, paras. 121, 124.

122 ILA, supra note 11, at point no. 6; ILA, supra note 113.