Introduction: On 29 December 2023, South Africa filed an application instituting proceedings against Israel before the International Court of Justice (ICJ), relying on the 1948 Convention on the Prevention and Punishment of the Crime of Genocide. The case concerns the situation in the Gaza Strip, with South Africa alleging that Israel has perpetrated genocidal acts targeting the Palestinian population as a national, racial, and ethnic group through its military campaign. Subsequently, on 26 January 2024, the Court issued a series of provisional measures, directing Israel to take immediate action to prevent any acts of genocide and to facilitate the provision of humanitarian assistance.

In relation to the ongoing proceedings, the Islamic Republic of Iran has announced its plan to participate as a non-party intervener. As stated by Mohammad Dehghan, Vice President for Legal Affairs, a national committee has been formed to compile the legal materials necessary to support South Africa’s submission. Importantly, Iranian officials have emphasized that they are not pursuing an independent application pursuant to Article IX of the Genocide Convention, as doing so could be interpreted as implicit recognition of Israel’s statehood.

Iran’s potential intervention introduces both procedural and substantive challenges, particularly with respect to the formal timeline for lodging declarations of intervention before the ICJ. This concern becomes more pronounced in the context of the recent trend of “mass interventions”, wherein over a dozen States have sought to engage in the proceedings pursuant to Articles 62 and 63 of the ICJ Statute. Although these interventions are nominally justified by reference to erga omnes obligations, the growing volume of third-party participation has sparked academic and institutional debate over the potential politicization of the Court’s adjudicative function and the strain placed on its judicial capacity.

This study investigates the normative basis, procedural nuances, and legal ramifications of third-party participation in proceedings before the ICJ, with particular attention to the South Africa v. Israel case. It analyzes Iran’s potential standing, the extent to which its position aligns with the Court’s established jurisprudence, and the broader issue of whether the current legal regime adequately differentiates between substantive legal interest and symbolic engagement in erga omnes scenarios. The paper also reflects on possible institutional reforms that may be required to preserve the Court’s judicial credibility and functional coherence.

Conclusion: Article 63 of the Statute of the International Court of Justice empowers States to participate in proceedings where the interpretation of a treaty to which they are contracting parties is under judicial consideration. In recent years, this mechanism has been invoked with increasing frequency, particularly in disputes involving the 1948 Genocide Convention. In Ukraine v. Russian Federation, thirty-two States submitted formal notices of intervention pursuant to Article 63, underscoring the need for a coherent interpretation of the Convention’s provisions and voicing concern over Russia’s alleged instrumentalization of the treaty’s language to legitimize military action. Likewise, in The Gambia v. Myanmar, seven States intervened to advocate for a uniform reading of the Convention in light of alleged crimes committed against the Rohingya population. These developments illustrate a growing appreciation for the interpretative dimension of Article 63 and its function in affirming the erga omnes partes nature of obligations arising under the Genocide Convention.

In view of previous cases where States party to the Genocide Convention have successfully relied on Article 63 of the ICJ Statute to intervene in matters involving treaty interpretation, it is reasonable to anticipate that comparable declarations in South Africa v. Israel will likewise be found admissible. The Court has consistently recognized such interventions as a valid procedural avenue through which States may articulate their interpretative positions regarding multilateral treaties to which they are signatories. This practice affirms the collective dimension of treaty obligations and enhances legal coherence by consolidating differing interpretations within a unified judicial setting. Nevertheless, this form of intervention is confined strictly to interpretative matters and does not confer party status upon the intervening State. As a result, the intervener does not acquire the procedural entitlements of the main litigants, and the binding force of the judgment is limited to the Court’s interpretation of the treaty provisions. In this context, any prospective intervention by Iran under Article 63 would not entail recognition of Israel either as a State or as a party to the proceedings. Simultaneously, the option of invoking Article 62 in the capacity of a non-party participant, akin to the procedural route initially pursued by Belize, remains open to Iran, though it is subject to a higher admissibility bar, namely, the requirement to demonstrate a concrete legal interest that could be impacted by the Court’s eventual ruling, as stipulated under Article 62.

Nevertheless, in view of the increasing volume of third-party intervention requests, many of which are substantively repetitive, Iran’s potential declaration under Article 63 would likely follow the prevailing pattern. Such a move may function more as a political expression of condemnation than as a meaningful contribution to the legal interpretation of the Convention. The accumulation of similar declarations risks overburdening the Court’s procedural framework without offering distinct interpretative value. In this context, and in light of the Court’s evolving procedural approach, alternative forms of engagement, such as providing legal or diplomatic support to the principal applicant, may offer a more effective and strategically coherent path for advancing shared legal and humanitarian objectives.

To address these procedural and normative concerns, a structural reform of Article 63 may be warranted. It is proposed that Article 63 of the ICJ Statute be amended to require intervening states to demonstrate an independent legal interest, akin to the threshold under Article 62. While the current formulation of Article 63 grants an automatic right of intervention to all treaty parties, this open-ended entitlement risks transforming the Court into a forum for political signaling rather than legal interpretation. Introducing a minimal threshold, such as requiring the intervening state to show how the interpretation of the treaty may affect its own legal obligations or implementation practices, would not only preserve the Court’s judicial integrity but also ensure that interventions remain substantively relevant and procedurally manageable. Such a reform would strike a necessary balance between inclusivity and discipline, reinforcing the ICJ’s role as a forum for principled adjudication rather than declaratory diplomacy.