Ten Years After the South China Sea Arbitration (2016–2026): Regional Legal Influence on ASEAN State Practice

Ten years after the 2016 South China Sea Arbitration, the Award remains formally final and binding between the Philippines and China, but its broader influence on Southeast Asia’s regional legal order remains insufficiently understood. Existing scholarship has primarily examined the Tribunal’s jurisdiction, maritime entitlements, bindingness, compliance, and bilateral consequences, while giving limited systematic attention to its reception in ASEAN state practice. This study examines the legal and diplomatic practices of four ASEAN states-the Philippines, Indonesia, Vietnam, and Malaysia between 2016 and 2026. Employing a qualitative socio-legal and comparative approach, it analyses the Award and UNCLOS alongside official diplomatic statements, notes verbales submitted to the United Nations, national legal positions, and relevant ASEAN declarations and statements. The comparative analysis identifies four differentiated patterns: legal invocation in the Philippines, confirmatory reception in Indonesia, strategic adaptation in Vietnam, and selective avoidance in Malaysia. The findings demonstrate that the Award has influenced legal arguments, maritime positions, and diplomatic discourse beyond its formal bilateral binding force. However, this influence remains uneven and has not developed into a collective ASEAN legal position. The study conceptualises this intermediate condition as Fragmented Regional Legal Influence, demonstrating how international adjudication may contribute to regional norm formation through differentiated state reception without extending formal binding force to non-party states.