China’s Declaration to the BBNJ Agreement: Strategic Multilateralism and Tactical Utilisation of Treaty Mechanisms

China ratified the Agreement under the United Nations Convention on the Law of the Sea on the Conservation and Sustainable Use of Marine Biological Diversity of Areas beyond National Jurisdiction ( BBNJ Agreement) on 15 December 2025. This was accompanied by three declaratory statements. This commentary analyses China’s declarations, with the view of assessing their legal import and their substantive significance in relation to the limitation to the temporal scope of the Agreement, the question of disputed areas, consensus-oriented decision-making, and the ‘not undermine’ principle. Through the declarations, we suggest, China strategically positions itself within a framework of multilateral cooperation while tactically seeking to insulate its core sovereign and economic interests from excessive legal spillover.