The Authority of ICJ Advisory Opinions as Precedents: The Mauritius/Maldives Case

The role played by precedents in international law is usually addressed with regard to their bearing on other judicial decisions and their contribution to the development of international law. Recently, the International Tribunal for the Law of the Sea (“ITLOS”) has offered a novel interpretation of the legal effects of the International Court of Justice’s (“ICJ”) advisory opinions as precedents. In Mauritius/Maldives, the ITLOS rejected two of the Maldives’ preliminary objections – based on the existence of a dispute between Mauritius and the United Kingdom over the sovereignty of the Chagos Islands – , arguing that the 2019 ICJ advisory opinion on the separation of the Chagos Archipelago from Mauritius had resolved the dispute in favour of the latter. In light of the ITLOS’s decision, the present contribution is aimed to provide some reflections on the authority of ICJ advisory opinions as precedents and on their legal effects in international law.