1 Continental Shelf (Libyan Arab Jamahiriya/Malta), Application to Intervene, Judgment of 21 March 1984, [1984] ICJ Rep. 3, at 18 ff., para. 28.

2 Intervention has been granted by the ICJ in three cases: Land, Island and Maritime Frontier Dispute (El Salvador/Honduras), Application by Nicaragua for Permission to Intervene, Judgment of 13 September 1990, [1990] ICJ Rep. 92; Land and Maritime Boundary between Cameroon and Nigeria (Cameroon v. Nigeria), Application by Equatorial Guinea for Permission to Intervene, Order of 21 October 1999, [1999] ICJ Rep. 1029; Jurisdictional Immunities of the State (Germany v. Italy), Application by the Hellenic Republic for Permission to Intervene, Order of 4 July 2011 (not yet published).

3 See, e.g., G. Guyomar, Commentaire du règlement de la Cour internationale de justice adopté le 14 avril 1978: Interprétation et pratique (1983), 533; Greig, D. W., ‘Third Party Rights and Intervention before the International Court’, (1992) 32 Virg. JIL 285Google Scholar, at 373.

4 See, in particular, S. Rosenne, Intervention in the International Court of Justice (1993), 196; Doussis, E., ‘Intérêt juridique et intervention devant la Cour internationale de justice’, (2001) 105 RGDIP 55Google Scholar, at 56; Palchetti, P., ‘Opening the International Court of Justice to Third States: Intervention and Beyond’, (2002) 6 MPYUNL 139Google Scholar, at 142 ff.

5 Territorial and Maritime Dispute (Nicaragua v. Colombia), Application by Honduras for Permission to Intervene, Judgment of 4 May 2011 (not yet published); Territorial and Maritime Dispute (Nicaragua v. Colombia), Application by Costa Rica for Permission to Intervene, Judgment of 4 May 2011 (not yet published); Jurisdictional Immunities of the State (Germany v. Italy), supra note 2. For a commentary on these decisions, see Forlati, S., ‘Intervento nel processo ai sensi dell'Art. 62 dello statuto: quale coerenza nella giurisprudenza della Corte internazionale di giustizia’, (2011) 94 Rivista di diritto internazionale (forthcoming)Google Scholar.

6 Neither Art. 62 of the Statute of the International Court of Justice nor Art. 81 of the Rules of Court clarifies in which capacity a third state may seek intervention.

7 Land, Island and Maritime Frontier Dispute (El Salvador/Honduras), supra note 2, para. 99. The possibility for a third state to intervene as a non-party had already been envisaged by Judge Oda in his 1981 Separate Opinion; see Continental Shelf (Tunisia/Libyan Arab Jamahiriya), Application by Malta for Permission to Intervene, Judgment of 14 April 1981, [1981] ICJ Rep. 3, at 23 ff. (Judge Oda, Separate Opinion).

8 The other common requirement is the ‘precise object of the intervention’ laid down by Art. 81 of the Rules of Court.

9 Territorial and Maritime Dispute (Nicaragua v. Colombia), Application by Honduras for Permission to Intervene, supra note 5, para. 37 (emphasis added). The same distinction is made by the Court in the Judgment concerning the Application by Costa Rica; see Territorial and Maritime Dispute (Nicaragua v. Colombia), Application by Costa Rica for Permission to Intervene, supra note 5, para. 26 (emphasis added).

10 See subsection 3.1, infra.

11 See Continental Shelf (Libyan Arab Jamahiriya/Malta), supra note 1, at 124 (Judge Ago, Dissenting Opinion); Territorial and Maritime Dispute (Nicaragua v. Colombia), Application by Honduras for Permission to Intervene, supra note 5 (Judges Al-Khasawneh and Keith, Declarations); Territorial and Maritime Dispute (Nicaragua v. Colombia), Application by Costa Rica for Permission to Intervene, supra note 5 (Judge Al-Khasawneh, Dissenting Opinion, and Judge Keith, Declaration).

12 See, in particular, Territorial and Maritime Dispute (Nicaragua v. Colombia), Application by Costa Rica for Permission to Intervene, supra note 5 (Judge Abraham, Dissenting Opinion).

13 See Rosenne, supra note 4, at 32; P. Palchetti, supra note 4, at 153–8; Forlati, S., ‘“Interesse di natura giuridica” ed effetti per gli stati terzi delle sentenze della Corte internazionale di giustizia’, (2002) 85 Rivista di diritto internazionale 99Google Scholar.

14 Barcelona Traction, Light and Power Company, Limited (Belgium v. Spain), Judgment of 5 February 1970, [1970] ICJ Rep. 3, at 35, paras. 44–46.

15 Territorial and Maritime Dispute (Nicaragua v. Colombia), Application by Costa Rica for Permission to Intervene, supra note 5, para. 6 (Judge Abraham, Dissenting Opinion).

16 Territorial and Maritime Dispute (Nicaragua v. Colombia), Application by Honduras for Permission to Intervene, supra note 5, para. 37. The Court made the same distinction in the decision concerning Application by Costa Rica, Territorial and Maritime Dispute (Nicaragua v. Colombia), Application by Costa Rica for Permission to Intervene, supra note 5, para. 26.

17 Ibid.

18 K. Mbaye, ‘L'intérêt pour agir devant la Cour internationale de Justice’, (1988/II) 209 RCADI 223, at 263.

19 Jurisdictional Immunities of the State (Germany v. Italy), supra note 2, para. 2 (Judge ad hoc Gaja, Declaration); see also Art. III(10) of the Resolution of the Institut de Droit International on ‘Judicial and Arbitral Settlement of International Disputes Involving More than Two States’, adopted in 1999 at the Berlin Session: ‘Intervention under Article 62 of the Statute of the International Court of Justice and similar texts in other statutes requires the existence of an interest of a legal nature on the part of the intervening State. That means that rights or obligations of this State under public international law can be affected by the decision’, available at www.idi-iil.org. It is doubtful whether the interest of the third state seeking to intervene could be based on municipal law. A claim based on municipal law would only be acceptable if consistent with international law. Thus, in the end, the legal interests that can be afforded protection before the ICJ are always ultimately based on international law; see subsection 3.3, infra.

20 Territorial and Maritime Dispute (Nicaragua v. Colombia), Application by Honduras for Permission to Intervene, supra note 5, para. 37; and Territorial and Maritime Dispute (Nicaragua v. Colombia), Application by Costa Rica for Permission to Intervene, supra note 5, para. 26: ‘it must in addition be possible for [the interest of a legal nature] to be affected, in its content and scope, by the Court's future decision in the main proceedings.’

21 Sovereignty over Pulau Ligitan and Pulau Sipadan (Indonesia/Malaysia), Application by the Philippines for Permission to Intervene, Judgment of 23 October 2001, [2001] ICJ Rep. 575, at 596, para. 47.

22 Land, Island and Maritime Frontier Dispute (El Salvador/Honduras), supra note 2, at 117, para. 61.

23 Monetary Gold Removed from Rome in 1943 (Italy v. France, United Kingdom of Great Britain and Northern Ireland and United States of America), Preliminary Question, Judgment of 15 June 1954, [1954] ICJ Rep. 19, at 32.

24 The object of the main dispute was to decide the question of whether the claim of the United Kingdom or of Italy to receive the gold removed from Rome in 1943 should have priority. This principal question necessarily entailed a decision on the preliminary question concerning the right of Italy to receive the gold and therefore on the asserted wrongful act committed by Albania against Italy. However, in order to decide the preliminary question – that is, to settle the dispute between Italy and Albania – would have required the consent of Albania (the third state). Indeed, the Court ‘can only exercise jurisdiction over a State with its consent’, ibid. Accordingly, the Court declined jurisdiction.

25 Land, Island and Maritime Frontier Dispute (El Salvador/Honduras), supra note 2, at 116, para. 56.

26 Jurisdictional Immunities of the State (Germany v. Italy), supra note 2, para. 25.

27 East Timor (Portugal v. Australia), Judgment of 30 June 1995, [1995] ICJ Rep. 90, at 90.

28 In the words of the Court: ‘the very subject-matter of the Court's decision would necessarily be a determination whether, having regard to the circumstances in which Indonesia entered and remained in East Timor, it could or could not have acquired the power to enter into treaties on behalf of East Timor relating to the resources of its continental shelf’, ibid., at 102, para. 28.

29 ibid., at 105, para. 34: ‘in this case, the effects of the judgment requested by Portugal would amount to a determination that Indonesia's entry into and continued presence in East Timor are unlawful and that, as a consequence, it does not have the treaty-making power in matters relating to the continental shelf resources of East Timor. Indonesia's rights and obligations would thus constitute the very subject-matter of such a judgment made in the absence of that State's consent.’

30 Certain Phosphate Lands in Nauru (Nauru v. Australia), Preliminary Objections, Judgment of 26 June 1992, [1992] ICJ Rep. 240, at 261, para. 55. For a discussion of this case, see the accompanying text to note 70, infra.

31 Land, Island and Maritime Frontier Dispute (El Salvador/Honduras), supra note 2, at 122, para. 73.

32 Territorial and Maritime Dispute (Nicaragua v. Colombia), Application by Honduras for Permission to Intervene, supra note 5, paras. 18 ff. (Judge Donoghue, Dissenting Opinion).

33 Land and Maritime Boundary between Cameroon and Nigeria, supra note 2, at 1034, para. 13.

34 Palchetti, P., ‘La protection des intérêts d'Etats tiers par la Cour internationale de Justice: L'affaire de la frontière terrestre et maritime entre le Caméroun et le Nigéria’, (2003) 107 RGDIP 865Google Scholar, at 869.

35 Today, intervention as a non-party can be considered as the ‘ordinary’ form of intervention. The Court has never granted permission to intervene as a party, and ‘si un Etat demande à intervenir sans rien préciser quant au statut qu'il revendique, la Cour considérera naturellement qu'il souhaite avoir le statut d'un intervenant qui n'est pas partie à l'instance’, Territorial and Maritime Dispute (Nicaragua v. Colombia), Application by Honduras for Permission to Intervene, supra note 5, para. 16 (Judge Abraham, Dissenting Opinion).

36 The existence of a jurisdictional link represents a major problem in this regard. It is not clear whether what is required is merely a ground of jurisdiction for the Court, or rather the consent of the parties to the main dispute.

37 Territorial and Maritime Dispute (Nicaragua v. Colombia), Application by Costa Rica for Permission to Intervene, supra note 5, para. 66.

38 Ibid., para. 67.

39 Ibid., para. 87.

40 Ibid., para. 89.

41 Ibid., para. 90.

42 See Territorial and Maritime Dispute (Nicaragua v. Colombia), Application by Costa Rica for Permission to Intervene, supra note 5, para. 14 (Judge Abraham, Dissenting Opinion), para. 10 (Judge Donoghue, Dissenting Opinion), and para. 2 (Judge ad hoc Gaja, Declaration).

43 Territorial and Maritime Dispute (Nicaragua v. Colombia), Application by Costa Rica for Permission to Intervene, supra note 5, para. 49. The Court held that the third state seeking to intervene ‘must explain with sufficient clarity its own claim . . . and the legal instruments on which it is said to rest, and must show with adequate specificity how [the decision of the Court on the main proceedings] might affect its claim’, ICJ, Sovereignty over Pulau Ligitan and Pulau Sipadan (Indonesia/Malaysia), supra note 21, at 598, para. 60 (emphasis added). But the Court also accepted that, at the preliminary stage in which the state applies for intervention, it should not provide ‘an exhaustive account of these interests’; Land, Island and Maritime Frontier Dispute (El Salvador/Honduras), supra note 2, at 130, para. 89. On the standard of proof relating to the legal interest, see C. Chinkin, Third Parties in International Law (1993), 163–9.

44 Territorial and Maritime Dispute (Nicaragua v. Colombia), Application by Costa Rica for Permission to Intervene, supra note 5, para. 51.

45 It seems unreasonable that the possibility offered by the Statute to the third state to protect its interests would depend first on the objections made by the parties to the main proceedings and subsequently on the ability of the Court to take these interests into account without permitting intervention. According to the Dissenting Opinion of Judge Abraham: ‘en tout état de cause, les éléments fournis par l'Etat requérant lors de la procédure relative à l'autorisation d'intervenir ne sauraient remplacer les informations et observations complètes que cet Etat pourrait soumettre une fois autorisé à intervenir’; ibid., para. 13 (Judge Abraham, Dissenting Opinion). See also the Declaration of Judge ad hoc Gaja, ibid., para. 1 (Judge ad hoc Gaja, Declaration).

46 Judge Abraham observed: ‘si la Cour est assez sage, sans avoir besoin à cette fin du concours d'aucun intervenant, pour ne pas rendre de décision qui préjudicierait aux intérêts des tiers, . . . il est, en bonne logique, inutile que quiconque lui demande l'autorisation d'intervenir, car la condition à laquelle l'article 62 du Statut subordonne l'intervention ne sera jamais remplie’; ibid., para. 26 (Judge Abraham, Dissenting Opinion). Or, more precisely, the condition can only be met if there are no alternative remedies.

47 See the Declaration of Judge ad hoc Gaja, ibid., para. 4 (Judge ad hoc Gaja, Declaration); see also McGinley, G. P., ‘Intervention in the International Court: The Libya/Malta Continental Shelf Case’, (1985) 34 ICLQ 671CrossRefGoogle Scholar, at 692.

48 See, in particular, Bartos, M., ‘L'intervention yougoslave dans l'affaire du Détroit de Corfou’, (1975) 14 Comunicazioni e Studi 41Google Scholar, at 50; C. Chinkin, supra note 43, at 226 ff.; P. Palchetti, supra note 4, at 165 ff.; Gaja, G., ‘A New Way for Submitting Observations on the Construction of Multilateral Treaties to the International Court of Justice’, in Fastenrath, U. et al. (eds.), From Bilateralism to Community Interests: Essays in Honour of Judge Bruno Simma (2011), 665CrossRefGoogle Scholar. For a favourable opinion in that regard, see, e.g., the Declaration of Judge ad hoc Gaja, Territorial and Maritime Dispute (Nicaragua v. Colombia), Application by Costa Rica for Permission to Intervene, supra note 5, para. 5 (Judge ad hoc Gaja, Declaration); and the Dissenting Opinion of Judge Donoghue, Territorial and Maritime Dispute (Nicaragua v. Colombia), Application by Honduras for Permission to Intervene, supra note 5, para. 59 (Judge Donoghue, Dissenting Opinion).

49 Territorial and Maritime Dispute (Nicaragua v. Colombia), Application by Costa Rica for Permission to Intervene, supra note 5, para. 89.

50 Ibid., para. 4 (Judge Abraham, Dissenting Opinion), and para. 22 (Judges Cançado Trindade and Yusuf, Dissenting Opinion).

51 The debated question is whether Art. 62 confers upon third states a ‘right’ to intervene. Although the Court seems to reply in the negative (Territorial and Maritime Dispute (Nicaragua v. Colombia), Application by Honduras for Permission to Intervene, supra note 5, para. 35), this statement could be interpreted as meaning that third states do not have ‘absolute rights’ under Art. 62. In any case, the key aspect is whether the Court has a discretionary power to grant permission to intervene or whether, the conditions of Art. 62 being met, the Court cannot deny intervention.

52 Continental Shelf (Tunisia/Libyan Arab Jamahiriya), supra note 7, para. 17; see also Continental Shelf (Libyan Arab Jamahiriya/Malta), supra note 1, at 151 (Judge Jennings, Dissenting Opinion); Territorial and Maritime Dispute (Nicaragua v. Colombia), Application by Honduras for Permission to Intervene, supra note 5, paras. 5–15 (Judge Abraham, Dissenting Opinion), and para. 32 (Judge Donoghue, Dissenting Opinion). On the policies of intervention, see C. Chinkin, supra note 43, at 180–4.

53 Territorial and Maritime Dispute (Nicaragua v. Colombia), Application by Honduras for Permission to Intervene, supra note 5, para. 75.

54 Ibid., paras. 66–70.

55 Ibid., paras. 71–74.

56 This is indeed the position taken by the Dissenting Judges. See, in particular, the Dissenting Opinions of Judge Abraham (Ibid., paras. 24–38 (Judge Abraham, Dissenting Opinion)) and Judge Donoghue (Ibid., paras. 39–54 (Judge Donoghue, Dissenting Opinion)).

57 Application by Germany instituting proceedings in the case concerning Jurisdictional Immunities of the State (Germany v. Italy), supra note 2, at 18.

58 Jurisdictional Immunities of the State (Germany v. Italy), supra note 2, para. 23.

59 Ibid., para. 25.

60 On the one hand, the would-be intervener has to produce all the evidence available in order to show that its legal interests may be affected, but, on the other hand, the Court should give a reasoned decision. Thus, Greece seems to have been exempted from the demanding burden of proof applied in the decision concerning Costa Rica's application to intervene. At the same time, even if it is common for the orders of the Court, when compared to judgments, to provide more succinct reasoning, this does not exclude the duty of the Court to assess the existence of the legal interest required by Art. 62.

61 Land, Island and Maritime Frontier Dispute (El Salvador/Honduras), supra note 2, at 116, para. 58 and at 135 ff., paras. 102–103. On the limited rights of the intervening state, see Quintana, J. J., ‘The Intervention by Nicaragua in the Case between El Salvador and Honduras before an Ad Hoc Chamber of the International Court of Justice’, (1991) 38 NILR 199CrossRefGoogle Scholar, at 204 ff.

62 Jurisdictional Immunities of the State (Germany v. Italy), Oral Pleadings, CR 2011/20, at 11.

63 Ibid., CR 2011/19.

64 If the legal interest that may be affected remains undefined and the intervening state ‘makes excursions in other aspects of the case’, a remedy can certainly be envisaged: the Court will not take into account the arguments of the intervening state. However, the problem remains that intervention has not fulfilled its function.

65 In addition, mere recognition of a foreign judgment should be distinguished from enforcement – that is, the adoption of measures of constraint vis-à-vis the foreign state; see, e.g., French Cour de cassation, SOABI v. Senegal, 11 June 1991, (1991) 118 Journal du droit international 1005: ‘ l'exequatur . . . ne constitue pas, en lui-même, un acte d'exécution de nature à provoquer l'immunité d'exécution de l'Etat considéré.’

66 In NML Capital Limited v. Republic of Argentina, 6 July 2011, [2011] UKSC 31, the UK Supreme Court held that ‘there is no principle of international law under which State A is immune from proceedings brought in State B in order to enforce a judgment given against it by the courts of State C, where State A does not enjoy immunity in respect of the proceedings that gave rise to that judgment’ (Lord Phillips, para. 29), but, under English law, in order to recognize a foreign judgment, the English court has to ascertain that the foreign court had jurisdiction, and duly respected the rules of international law on immunity.

67 For a case in which such reasoning led Belgian courts to deny the enforceability of the Greek judgment in the Distomo case, see Tribunal de Bruxelles, order of 26 October 2005, RR.05/3092/B (d'Argent, P., ‘Jurisprudence belge relative au droit international public’, (2007) 40 RBDI 149Google Scholar, paras. 43–45).

68 Intervention has been denied when the claims of third states involved a new dispute that was separate from the dispute at issue in the main proceedings. Since intervention is an incidental proceeding, it should relate to the subject matter of the dispute before the Court in the main proceedings and should not amount to the submission of a new case. See, in particular, Continental Shelf (Tunisia/Libyan Arab Jamahiriya), supra note 7, paras. 31–33; Continental Shelf (Libyan Arab Jamahiriya/Malta), supra note 1, at 19 ff., paras. 29–34.

69 Application for Permission to Intervene submitted by the Government of Fiji in the Nuclear Tests Case (New Zealand v. France), 18 May 1973, at 3.

70 Application for Permission to Intervene submitted by Nauru, in the case concerning Certain Phosphate Lands in Nauru (Nauru v. Australia), 13 May 1989, at 30, 32.

71 Certain Phosphate Lands in Nauru (Nauru v. Australia), supra note 30, at 255, para. 39. Australia argued that ‘any decision of the Court as to the alleged breach by Australia of its obligations under the Trusteeship Agreement would necessarily involve a finding as to the discharge by [New Zealand and the United Kingdom] of their obligations in that respect, which would be contrary to the fundamental principle that the jurisdiction of the Court derives solely from the consent of States’, ibid., at 259, para. 49.

72 ibid., at 261, para. 55 (emphasis in original).

73 ibid. (emphasis added).

74 Although the Court did not specify whether they would be entitled to do so, it added that ‘the absence of such a request in no way precludes the Court from adjudicating upon the claims submitted to it, provided that the legal interests of the third State which may possibly be affected do not form the very subject-matter of the decision that is applied for’; ibid., at 261, para. 54.

75 Mbaye, supra note 18, at 292: in the case of intervention, the legal interest must be ‘personnel et concret’ and should not be ‘impersonnel et théorique’.

76 See note 84, infra, and accompanying text.

77 Land, Island and Maritime Frontier Dispute (El Salvador/Honduras), supra note 2, para. 76.

78 See also Continental Shelf (Tunisia/Libyan Arab Jamahiriya), supra note 7, at 17, para. 30.

79 Sovereignty over Pulau Ligitan and Pulau Sipidan (Indonesia/Malaysia), supra note 21, at 603 ff., para. 83.

80 Jurisdictional Immunities of the State (Germany v. Italy), Oral Pleadings, CR 2011/19 (translation), para. 8.

81 Ibid., para. 10.

82 Ibid., para. 114.

83 Ibid., para. 126.

84 To use the words of the International Law Commission, for a state to be admitted to proceedings as an intervener, ‘it must be affected by the [decision of the Court] in a way that distinguishes it from the generality of other [third] States’ that may be concerned by the decision of the Court (ILC Commentary on Article 42 of the Draft Articles on State Responsibility, 2001 YILC, Vol. II (Part Two), at 119, para. 12).

85 For the possibility to open intervention to states affected by the breach of an erga omnes obligation, see, in particular, Art. 4 of the Resolution of the Institut de droit international on ‘Erga Omnes Obligations in International Law’, adopted in 2005 at the Krakow Session (available at www.idi-iil.org); and Forlati, S., ‘Azioni dinnanzi alla Corte internazionale di giustizia rispetto a violazioni si obblighi erga omnes’, (2001) 84 Rivista di diritto internazionale 69Google Scholar, at 108.