Abstract Facing Mongolia’s refusal to arrest the sitting head of the Russian Federation and surrender him to the Court, the International Criminal Court (ICC) in October 2024 was confronted one more time with the issue concerning the extent to which heads of state are entitled to personal immunity before international jurisdictions. This article examines the legal reasoning of the non-compliance decision issued by the ICC, arguing that it marks a clear departure from the Court’s precedent, which referred either to customary law or to the Security Council’s powers under Chapter VII of the United Nations Charter. It suggests that although the decision at issue constitutes a remarkable attempt to reaffirm the obligations of state parties to cooperate in good faith with the ICC, its teleological approach conflicts with the principle enshrined in Article 34 of the Vienna Convention on the Law of Treaties. The article analyses the different interpretations of the relevant provisions of the Rome Statute, and expands to include a critical analysis of the customary international law on the matter, suggesting that the rules concerning head of state personal immunity vis-à-vis an international court are not a derogation or exception from traditional customary law. It affirms that head of state immunity has never been recognized in international law as a bar to the jurisdiction of an international court and that such immunity may not be pleaded before the ICC according to current customary law. Finally, the article suggests that the ICC instead of anchoring its decision solely on the Rome Statute, could have better decided the case by relying on customary international law and developing its existing jurisprudence.
Raffaella Calò (2025) studied this question.