When restraint is tested: ASEAN, China, and the future of the code of conduct

Under the Philippines’ ASEAN Chairship, ASEAN leaders are meeting again to finalize a code of conduct (CoC) for the South China Sea (SCS).

In 2002, ASEAN and China issued the Declaration on the Code of Parties (DoC) in the South China Sea, which aimed to underscore the importance of aligning member states’ conduct in the SCS with the UN Charter, the United Nations Convention on the Law of the Sea (UNCLOS), and the Treaty of Amity and Cooperation principles. ASEAN and China also declared that they would promote exercising self-restraint, which at that time was phrased to include refraining from escalation, from occupying uninhabited islands and features, and settling their differences. Going back to the essence of the DoC is significant, as it reveals the ASEAN’s bare minimum desires, which include peaceful settlement of disputes, maritime functional cooperation, and confidence-building measures.

In 2026, however, it has become difficult to raise expectations that the ASEAN and China will be able to address the bottlenecks that have accompanied debates over the code’s legality and binding nature, its geographic scope, the form of dispute settlement, and the operationalization of self-restraint — the latter perhaps foremost among these. Foreign Affairs Secretary Ma. Theresa P. Lazaro has said that her work as the Philippines’ chair of the ASEAN is guided not only by optimism but also by pragmatism, which leads us to ask a familiar question: Is there hope for a South China Sea code of conduct? What role can it still play in promoting meaningful self-restraint?

My take is to adopt a pragmatic approach and argue for pushing for the code as an indispensable mechanism for managing crises that, as analysts have warned, could push certain countries, including the Philippines, to the brink of war in the South China Sea.

Recent developments have markedly altered our already asymmetrical relationship with China, as well as the conditions in the West Philippine/South China Sea, where China has openly eroded the DoC’s principle of self-restraint. There are three focal points of escalation of China’s aggression: the Panatag/Scarborough, Ayungin/Second Thomas, and Escoda/Sabina shoals, where control of these features would tighten China’s hold on vital shipping lanes and waterways, providing military footholds for its nine-dash line claims while directly challenging the Philippines’ sustained and lawful claims to the West Philippine Sea.

Since 2024, China’s actions in these areas have resulted in dangerous collisions, including the June 17, 2024, incident, which seriously injured a Philippine Navy sailor who lost a thumb. Additionally, the more recent Aug. 11, 2025, collision involved a large Chinese navy destroyer that collided with a Chinese Coast Guard vessel, an incident that could have killed Chinese citizens and which China did not publicly disclose. The same incident could have killed Filipinos had the Chinese vessel successfully rammed the Philippine ship it was pursuing. Against this backdrop, regional elites are increasingly pressing the United States to publicly clarify the threshold for invoking the 1951 PHL-US. Mutual Defense Treaty, arguing that clearer red lines would strengthen deterrence and regional stability.

Further altering the status quo in the West Philippine/South China Sea is President Ferdinand “Bongbong” Marcos, Jr.’s response: one that has shifted what scholars refer to as “alliance-led resistance.” This approach, however, has been de-risked by diversifying partnerships with like-minded states and by harnessing a comprehensive archipelagic defense posture that underpins Philippine maritime security. It is within this alliance-centered and defense-oriented framework that on Aug. 11, 2025, Mr. Marcos also openly acknowledged the Philippines’ potential embroilment in the Taiwan conflict, saying that “we do not want to go to war, but I think if there is a war over Taiwan, we will be in drawn… hihilahin tayo sa ayaw man o sa gusto natin (we will be pulled in whether we want to or not)… kicking and screaming, we will be drawn and dragged into that mess.” In doing so, he not only publicly situated the Philippines within a possible US response to a China invasion of Taiwan, but also crystallized a South China Sea-Taiwan nexus that amplifies escalation risks across theaters.

Against this backdrop, expectations surrounding the Code of Conduct have become more restrained. For the Philippines, the increasingly complex strategic environment has highlighted the difficulty, but also the necessity, for it to balance engagement with realism, as it contends with the imperative of translating the ASEAN DoC’s political commitments into meaningful self-restraint, while managing diplomacy, alliance relations, and external defense.

Alma Maria O. Salvador, PhD, is an associate professor of Political Science at the Dr. Rosita G. Leong School of Social Sciences, Ateneo de Manila University. is an associate professor of Political Science at Ateneo de Manila University.