The Nicaragua v. Colombia II case and the identification of the customary rules concerning the delimitation of the continental shelf beyond 200 nautical miles

Abstract

This article aims to provide an analysis of the case concerning the delimitation of the continental shelf beyond 200 nautical miles (Nicaragua v. Colombia), decided by the International Court of Justice in 2023, focusing on the conclusions regarding customary international law related to the delimitation of this portion of the maritime territory of the States. To achieve this objective, the relationship between the legal regimes of the exclusive economic zone and the continental shelf in customary international law, the interaction of the International Court of Justice with the jurisprudence of other international courts in identifying the applicable rules, as well as the methodology employed to identify custom and its constitutive elements in the case, are examined. The study concludes that, in this case, the Court does not depart from its previous jurisprudence, reiterating some previously identified trends, but seems to undermine the persuasiveness of the legal reasoning developed to identify customary law concerning the delimitation of the extended continental shelf.