The Revival of Third-State Participation Before the International Court of Justice: Rethinking Intervention Under Articles 62 and 63

The growing practice of third-state intervention before the International Court of Justice (ICJ) reflects an important development in international adjudication, particularly in disputes concerning multilateral treaty obligations. This article examines the evolving relationship between Articles 62 and 63 of the ICJ Statute, focusing on their distinct legal foundations, admissibility requirements, and implications for the participation of non-party states. While Article 62 requires a state to demonstrate an interest of a legal nature that may be affected by the Court’s decision, Article 63 provides a treaty-based right of intervention to states that are parties to the relevant multilateral convention. The comparatively accessible requirements of Article 63 have contributed to its increasing prominence in contemporary proceedings. Drawing primarily on Ukraine v. Russian Federation, alongside The Gambia v. Myanmar and South Africa v. Israel, the article analyses the expansion of third-state participation, particularly in disputes concerning the Convention on the Prevention and Punishment of the Crime of Genocide. It further examines concerns regarding political alignment, judicial impartiality, and the potential abuse of process arising from mass intervention. The analysis argues that political motivations alone should not render an intervention inadmissible where the applicable legal requirements are satisfied. Nevertheless, a valid procedural basis should not automatically immunise intervention from scrutiny where clear evidence of procedural misuse exists. The article concludes that the growing use of Article 63 presents both opportunities and institutional challenges for the ICJ. Although third-state participation can enrich treaty interpretation and facilitate the collective development of international law, its exercise must remain within the permissible scope of intervention and preserve the integrity and orderly administration of international judicial proceedings.