Ten Years of the South China Sea Arbitral Award
- June 23, 2026 |
- IDSA Comments
The anniversary of the arbitral ruling is of particular significance in 2026 as the Philippines is the ASEAN Chair and also coincides with ASEAN’s efforts to conclude a legally binding SCS Code of Conduct. The Philippines also hosts the ASEAN Maritime Centre, whose establishment was approved at the 48th ASEAN Summit in May 2026, held in Cebu.[3] These developments have placed Manila at the centre of regional efforts to strengthen maritime cooperation and manage escalating tensions in one of the world’s most vital waterways.
A Landmark in International Maritime Law
The arbitration was initiated by the Philippines in 2013 to seek clarification regarding maritime entitlements and the legality of China’s maritime claims. The tribunal’s 2016 ruling concluded that China’s claim to historic rights within the nine-dash line had no legal basis under UNCLOS.[4] Furthermore, the ruling clarified that none of the disputed features in the Spratly Islands qualified as entitled islands capable of generating a 200-nautical-mile Exclusive Economic Zone (EEZ).[5] The tribunal found that China violated the Philippines’ sovereign rights within its EEZ by intervening with fishing and petroleum exploration activities.
China rejected the ruling and declared it ‘null and void’ and further expanded its maritime military activities and naval presence across the contested waters. Rampant confrontations involving Chinese vessels and the Philippines’ military have been witnessed around Second Thomas Shoal and Scarborough Shoal. Before the ruling, the SCS was often viewed as a context of overlapping historical claims. However, the debate has now become more about defending a rules-based order.
Between 2013 and the current dynamics, China has created around 3,200 acres of artificial islands in the Spratlys.[6] The 2016 ruling also points out that Beijing may disregard international law when it concerns securing its own interests and validate it when it concerns criticising the US.
Ten years after the ruling, the paradox surrounding arbitral awards is quite striking. While the legal authority of the decision has strengthened, enforcement challenges persist. The award has been deeply embedded in the international diplomatic discourse. Several countries, such as the US, Japan, India and Australia, have affirmed the ruling’s relevance and emphasised the centrality of UNCLOS to maritime governance. The decision has also become a reference point for freedom-of-navigation operations and regional security dialogues. The SCS today is more contested and militarised than it was in 2016. The strategic rivalry between the US and China has also intensified, and China sees the SCS as a contest for regional hegemony and US Containment.
The Evolving Approach of the Philippines
Over the past decade, the Philippine policy towards the arbitral award has evolved across different administrations, reflecting changing domestic priorities and regional circumstances. The Rodrigo Duterte administration (30 June 2016–30 June 2022) adopted a conciliatory approach towards China, focusing on economic engagement and dialogue while also maintaining the award’s legal validity. However, since July 2022, the Ferdinand Marcos Jr. administration has emphasised assertiveness and the defence of Philippine rights in the SCS. The Philippines’ decision to pursue legal action against China was seen as an instance of lawfare aimed at countering China’s moves in the SCS.
In recent years, the Philippines has adopted a more assertive stance regarding its maritime rights. The government has invoked the arbitral ruling in protests, international forums and also public communications. Maritime transparency initiatives, strengthening coast guard operations, and deepening security cooperation with external partners reflect a renewed commitment to defending rights recognised under international law.
Under President Ferdinand Marcos Jr., the Philippines has focused on greater institutionalised cooperation with the US, Japan and Australia. Furthermore, at the Shangri-La Dialogue held in Singapore on 31 May 2026, Philippine Secretary of National Defence Gilberto Teodoro Jr. remarked that China is the biggest challenge for ASEAN member states due to its claims in the SCS.[7] In response to his remarks, China imposed sanctions on him by prohibiting his entry into China.
The coincidence of the tenth anniversary with the Philippines’ ASEAN Chairmanship also creates an opportunity for regional leadership. ASEAN has struggled to formulate a response to the SCS disputes due to divergent national interests among member states. While some ASEAN countries are claimants in the SCS, others prioritise economic ties with China, reflecting a cautious approach. The Philippines has been the most outspoken Southeast Asian country to defend its claims against China’s encroachments.
The Philippines, as ASEAN chair, brings all member states together by building on the gains of Malaysia’s theme of Inclusivity and Sustainability. The Philippines’ theme of ‘Navigating our Future Together’ is also along the same lines. The Philippines is also well-positioned to encourage greater ASEAN consensus on principles, including respect for UNCLOS, freedom of navigation, environmental protection, and the avoidance of coercive actions at sea.
Moreover, the anniversary of the arbitral ruling provides Manila with a platform to reinforce the idea that an arbitral award is not a bilateral issue between the Philippines and China but rather a broader affirmation of the international maritime legal order. By framing the ruling as a way of contributing to regional stability, the Philippines can help strengthen ASEAN’s position on maritime governance. The award, therefore, provided legal legitimacy to Manila’s claims.
The establishment of the ASEAN Maritime Centre also adds significance to the tenth anniversary. The centre has wide potential to become an institutional mechanism for maritime cooperation across Southeast Asia. Its activities can contribute to maritime domain awareness, capacity-building, and search-and-rescue coordination. The centre also seeks to build habits of cooperation among regional stakeholders. While the arbitral award provided the legal framework for maritime rights, the Centre can facilitate the practical implementation of cooperative maritime governance. The Centre’s establishment in the Philippines positions it as a hub for fostering maritime cooperation.
Concluding Remarks
A decade after the landmark arbitral award of July 2016, its relevance remains undiminished. The award did not resolve sovereignty disputes, but it reshaped the legal and diplomatic landscape surrounding the contested maritime region. It also established a baseline against which future nations’ behaviour would be judged. The award also showed that international law can provide smaller states with meaningful avenues to challenge claims, clarify legal rights, and reframe the authority of the UNCLOS. The tribunal award has also prevented excessive maritime claims from being accepted as legal.
ASEAN member states should continue to invoke UNCLOS and focus on maintaining the rules-based order as the basis of maritime governance. Negotiations for an SCS Code of Conduct continue, but there are questions and doubts over any meaningful outcome from those negotiations. In an era of strategic rivalries and great-power competition in a volatile and complex security environment, the core message of maintaining peace through UNCLOS and ensuring a rules-based order remains relevant even today as it was a decade ago.
[1] “The South China Sea Arbitration (The Republic of the Philippines v. The People’s Republic of China), PCA Case No. 2013-19”, Permanent Court of Arbitration, 12 July 2016, pp. 23–29.
[2] Ibid.
[3] “Chair’s Statement of the 48th ASEAN Summit”, ASEAN Main Portal, 8 May 2026.
[4] “The South China Sea Arbitration (The Republic of the Philippines v. The People’s Republic of China), PCA Case No. 2013-19”, no. 1, p. 254.
[5] Ibid.
[6] Ibid., p. 445.
[7] Raissa Robles, “China’s Ban on Philippine Defence Chief and Family Seen as Warning Shot to Manila”, South China Morning Post, 12 June 2026.
