International treaty law and contested statehood: Managing bilateral relations in multilateral treaties

Abstract This study examines how contested statehood is navigated in the ambit of the common participation in a multilateral treaty, focusing on a bilateral legal relationship between a non-recognizing state and an entity with disputed statehood. Using the case of Serbia and Kosovo, the research explores how a state that does not recognize another entity strategically navigates their shared participation in multilateral agreements. It analyses legal tools available to non-recognizing states to safeguard their national interests, including statements of non-recognition, objections to accession, engagement with treaty depositaries, and territorial clauses. The findings demonstrate that statements of exclusion are the most legally effective instrument for preventing the establishment of bilateral treaty relations while other mechanisms primarily serve the communicative function. The study highlights the dual role of international law, as both a legal framework governing treaties and a strategic tool for states to manage contested sovereignty within multilateral treaties.