Intervention and obligations erga omnes at the International Court of Justice

Benjamin Salas Kantor
Research Scholar at Columbia Law School
Dr. Massimo Lando
Assistant Professor at the School of Law of City University of Hong Kong and Global Fellow at CIL

Published on 20 April 2023

It is not too often that one attends a conference and witnesses an unexpected fine technical debate on the reading of the Statute of the International Court of Justice (ICJ). This year, it happened at the Annual Meeting of the American Society of International Law. In a session about multilateral litigation before the ICJ, held on 31 March 2023, some of the speakers offered conflicting views on Article 62 of the Court’s Statute. Article 62 concerns intervention and provides that, ‘[s]hould a state consider that it has an interest of a legal nature which may be affected by the decision in the case, it may submit a request to the Court to be permitted to intervene’ (emphasis added). The debated question was whether an application for intervention under Article 62 of the Statute should be, in principle, granted purely on the basis that the respondent State has allegedly breached obligations erga omnes. This question may arise in disputes concerning aggression, genocide, racial discrimination, or self-determination (see Barcelona Traction, para. 34). These are matters on which recent cases before the Court have touched.

The positions of the panellists

The debate took place among three participants: Ben Juratowitch, Brian McGarry and Pierre d’Argent. Ben Juratowitch was of the view (see minute 30) that, in principle, the Court should grant a request for intervention under Article 62 where the applicant State alleges the breach of obligations erga omnes. An interest in the fulfilment of obligations erga omnes would qualify as ‘an interest of a legal nature’ of the State applying to intervene. Juratowitch recalled the Court’s decision in Barcelona Traction, in which the Court held that ‘in view of the importance of the rights involved, all States can be held to have a legal interest in their protection; they are obligations erga omnes’.

Brian McGarry held the opposite view (see minute 23), for two reasons. The first reason was that the raison d’être of the erga omnes doctrine was that, without it, a State could evade accountability by breaching fundamental rules in a way that did not directly injure any particular State. That purpose, according to him, was satisfied as soon as a State instituted proceedings and would not be furthered by adding intervening States. The second reason was that the drafters of the PCIJ’s Statute, from which Article 62 originates, did not envision an international adjudication system where third States would frequently be intervening in cases in which they had no direct injury. In his reading of the practice of the Court, Article 62 requires a ‘particularized interest’, which is not met by applying to intervene merely based on the relevance of protecting obligations erga omnes in the case concerned.

Pierre d’Argent, who was sitting in the audience, took the microphone (see minute 46) and attempted to settle the debate. He agreed with Juratowitch that the term ‘interest of a legal nature’ includes an interest in the fulfilment of obligations erga omnes, but argued that this is not the end of the story. He recalled that Article 62 not only requires an interest of a legal nature but also that such an interest ‘may be affected by the decision’ of the Court. He emphasized that the crux is in these words, which would create a requirement of ‘particularization’ of the legal interest in Article 62 interventions. He then concluded that it was doubtful whether, if an obligation erga omnes was at stake, the Court’s future decision would necessarily affect, within the meaning of Article 62, the interest of any state in the international community.

Taking stock

The question of intervention, under Article 62, raises in fact two questions: (1) whether the State seeking to intervene has an ‘interest of a legal nature’; and (2) whether that interest ‘may be affected’ by the Court’s decision. The twofold test is consistent with the Court’s approach in Nicaragua v. Colombia and El Salvador/Honduras.

On the first question, we share the views of Juratowitch and d’Argent: there seems to be no good reason to consider that the fulfilment of obligations erga omnes by the Respondent could not, in principle, constitute an ‘interest of a legal nature’ for the purpose of intervention. McGarry is right to point out that the statutory rules on intervention are distinct from the rules governing the institutions of proceedings. The question arises, however, as to why a State would be able to file an application instituting proceedings based on the alleged breach of obligations erga omnes but, at the same time, be unable to intervene based on its interest in protecting those very obligations. Such an approach seems rather formalistic. As Juratowitch pointed out, even though Barcelona Traction did not deal with the admissibility of applications for intervention, the Court’s statements were broad enough to convey that all States have a ‘legal interest’ in the protection of obligations erga omnes. Nothing in Barcelona Traction suggests that this view cannot extend to intervention under Article 62 (Judge Keith, in Nicaragua v. Colombia, thought differently).

The second question is more difficult to answer because of the Court’s approach to intervention under Article 62, which is not entirely clear. That approach is not entirely restrictive. First, a State does not bear the burden of showing that its legal interest ‘will’ or ‘is likely to’ be affected by the decision, but only that it ‘may be’ affected (El Salvador/Honduras, para. 61). Second, it is sufficient to show that the legal interest may be affected by the reasoning of the Court, regardless of the dispositif sought (Indonesia/Malaysia, para. 47). Third, a State applying to intervene does not have to claim a legal right or establish injury as it is sufficient for it to show that its legal interest ‘may be’ affected (El Salvador/Honduras, para. 24).

However, the Court has placed sufficient admissibility hurdles to make interventions difficult to succeed, even though Article 62 is framed in rather permissive language. First, a State seeking to intervene will necessarily have ‘to show in what way [its legal] interest may be affected’ by the decision (El Salvador/Honduras, para. 61). The Court’s jurisprudence is not clear-cut as to the sort of nexus necessary to meet that requirement. At least, that jurisprudence suggests that the nexus likely is case-dependent, which is not necessarily clarificatory. Second, a would-be intervener will likely be unsuccessful if it simply argues that the Court’s pronouncement may affect its understanding of applicable rules of international law (Libya/Malta, para. 30). In other words, it must be possible for the legal interest to be affected in its content and scope, which must be more than mere concern with ‘the general legal rules and principles likely to be applied’ (El Salvador/Honduras, para. 76 and Indonesia/Malaysia, para. 83). Third, the Court has held that the interest on which a State relies in seeking to intervene cannot be ‘too remote’ and has to be the object of ‘a real and concrete claim of that State, based on law, as opposed to a claim of a purely political, economic or strategic nature’ (Nicaragua v. Colombia, para. 77). That interest will be assessed ‘in concreto and in relation to all the circumstances of a particular case’ (El Salvador/Honduras, para. 61).

Where does the Court’s approach leave a State seeking to intervene when an obligation erga omnes is at stake? In a difficult but not impossible scenario. That State’s key task will be to persuade the Court that there is a sufficient connection between its own interest in the protection of an obligation erga omnes, on the one hand, and the possibility that the Court’s reasoning or decision in the main proceedings may affect that interest to protect the obligation erga omnes, on the other hand. That nexus may well lie in the Court’s interpretation of the content and scope of the obligation erga omnes, or in the dispositif, given that any of those pronouncements may affect the understanding of an obligation that is owed to the would-be intervener, and thus, affect its legal interest in protecting that obligation. For example, the Court’s decision may affect the legal interest of the intervening State because its reasoning can guide the future conduct of that State. This, in our view, would meet the Article 62 test.

Furthermore, as Judge Oda stated in Libya/Malta, when it comes to obligations erga omnes, a third State is ‘equally affected’ by their breach as an applicant State is and, in principle, the two States share the same interest. If an applicant State has standing, so should an Article 62 intervener. Judge Gaja, in his Hague Academy lecture, and other scholars, held a similar view and considered that ‘whatever interest of a legal nature is required in Article 62, it cannot be higher than the one that justifies bringing a claim before the Court’.

Looking ahead: a case for reform?

There seem to be good arguments to allow Article 62 interventions in the terms set out above. Yet, the Court’s cautious jurisprudence may make such interventions difficult to accomplish. One should thus think of avenues alternative to intervention. The Institut de droit international, at its 2005 Krakow Session, took the view that a State to which an obligation erga omnes is owed should have the possibility to participate in proceedings pending before the Court. It appears significant that the Institut did not refer to ‘intervention’ but to ‘participation’. This reference suggests that the Court could create alternative procedures for third States to participate in proceedings before it without having to intervene. A welcomed development could be the introduction of an amicus curiae procedure, which, short of intervention, would allow States to present their views with regard to obligations that are owed erga omnes. The idea has been discussed in literature and, in general terms, appears supported by Judges Gaja and Donoghue in Territorial and Maritime Dispute (Nicaragua v. Colombia).

Amici curiae are known to international courts and tribunals. The European Court of Human Rights, the Inter-American Court of Human Rights and the WTO dispute settlement bodies allow third parties to submit amici curiae. The Court could follow suit by amending its Rules of Procedure, pursuant to the power under Article 30(1) of its Statute. An amendment to the Rules seems desirable, especially to set the limits within which third States could submit amici curiae. Irrespective of that amendment, the ICJ, as a court of law, can investigate points of fact and law arising in cases before it. The Court may justify accepting amici curiae by reference to these investigative powers. The ECtHR, before adopting a specific rule on amici curiae, allowed the submission of amici briefs in Young, James and Webster v. The United Kingdom precisely based on its investigative powers. If amici curiae were accepted without (or before) amending the Rules, the Court could proceed by analogy with the rules on advisory proceedings. Article 60(2) of the Statute provides that the Court may request any State or organisation ‘likely to be able to furnish information’ to submit such information to it. Without having actively to seek information from third States in contentious cases, the Court may limit itself to accepting the submission of information likely to be beneficial to decide the case before it.

The danger of not amending the Rules of Court is that the limits within which States can submit amici curiae would remain unclear. For instance, it would be unclear whether there is a time-limit to submit amici curiae, whether only certain States (and which ones) may submit them, whether they would be included in the case file, and how the Court may use them in its decision-making process. If the Rules are not amended, all these questions would have to be decided by the Court itself in a case-to-case basis, which could generate criticism. One aspect emerges nonetheless: the Court’s Article 62 jurisprudence has been complicated enough to have prevented intervention in most cases in which States have applied for it. Introducing a new amicus curiae procedure could skirt the rigidity of Article 62 intervention. Specifying the limits of this new procedure in the Rules could also discourage possible abuses.