The Role of International Law in the South China Sea Dispute: A Case Study of the 2016 Permanent Court of Arbitration Ruling

The South China Sea dispute stands as a complex intersection of international law, geopolitics, and regional security, involving competing territorial and maritime claims from China, the Philippines, Vietnam, Malaysia, Brunei, and Taiwan. Central to this thesis is the analysis of the 2016 Permanent Court of Arbitration (PCA) ruling, which declared China's expansive “Nine-Dash Line” claim incompatible with the United Nations Convention on the Law of the Sea (UNCLOS). Despite the ruling’s clear legal reasoning and reaffirmation of UNCLOS principles, China’s refusal to recognize and comply with the judgment highlights the critical limitations of international legal enforcement when challenged by major powers. This study examines the effectiveness of the PCA ruling in shaping state behavior, the role of international and regional organizations such as ASEAN in dispute resolution, and the broader tension between legal norms and geopolitical interests. Drawing from legal theory, compliance studies, and international relations perspectives, the research reveals how the South China Sea case illustrates the fragile authority of international law in constraining powerful states. It further explores the implications for regional stability, maritime governance, and the evolving balance between law, sovereignty, and realpolitik in international order. The findings emphasize that while international law remains a vital framework for peaceful dispute resolution, its success ultimately depends on political will, diplomatic engagement, and multilateral cooperation.