Study on the ‘Legal Effect’ of the Advisory Opinion of the ICJ in Determining the Existence of Dispute

Abstract

Determining the existence of dispute is a crucial matter for the progression of entire judicial proceedings in international law. In this regard, the judgment rendered by the Special Chamber of the International Tribunal for the Law of the Sea concerning Preliminary Objections raised in the recent Dispute Concerning Delimitation of the Maritime Boundary Between Mauritius and Maldives in the Indian Ocean case was quite noticeable. In this case, the Special Chamber determined that the dispute concerning sovereignty over the Chagos Archipelago between Mauritius and the UK does not exist, based on the ICJ’s Advisory Opinion delivered in 2019. Although it has been widely acknowledged that the Advisory Opinion of the ICJ may have a certain ‘legal effect’ on the disputed matters between states, it was not clearly given exactly what that legal effect is. However, in Mauritius/Maldives case, the Advisory Opinion of the ICJ was confirmed as a new element which must be considered in determining the existence of a dispute. And accordingly, the Special Chamber found that due to the legal effect of the Advisory Opinion on the matter of the separation of the Chagos Archipelago, the sovereignty dispute over this region ceased to exist. This judgment implied the legal effect of the Advisory Opinion on the status of a certain on-going dispute and how it affects. The Special Chamber’s determination on the existence of the dispute may have a substantial impact on the future international adjudicative practice in general. First, considering the tendency of ‘cross-fertilization’ between international courts and tribunals, the Special Chamber’s decision would also become a new referencing point for other courts and tribunals in determining the existence of dispute in similar circumstances. Secondly, this case will also affect the practice of UNCLOS Part XV in so-called ‘mixed dispute’ cases in dealing with jurisdictional matters. Lastly, Advisory Opinions not only given by the ICJ but by other judicial bodies would also have an impact on the future judicial proceedings where the existence of a certain dispute is contested.