International Law and Conflict Disputes: The Case of the South China Sea
While the South China Sea disputes are not legally resolved, the context of the South China Sea today is meaningfully different than it was in 2012, when the People’s Republic of China took control of Philippine-owned Scarborough Shoal and China was actively creating artificial islands and militarizing them. Deterring China from taking control of any further maritime features has been effective, which should be considered a partial victory. There are many interpretations of the explanation for such deterrence and the current context of maintaining the status quo without any Chinese escalation in the past thirteen years. This article highlights four factors that build upon each other in an interconnected way: 1) the 2016 arbitration case between the Philippines and China, 2) a shift in policy position about the role of the United States in the South China Sea, 3) increased naval operations and joint military exercises by the United States, non-disputant states in the Indo-Pacific region, Canada, and European Union states, and 4) the increased resolve of disputant states to defend themselves against China.
When the Philippines filed complaints against Chinese actions through an Annex VII arbitration panel in 2013, there was a good guess that China would not show up to the arbitration. Thus, it was not surprising for the Philippines that China rejected rulings that the Philippine government correctly predicted would be found in their favor. Some observers have claimed that the arbitration case was useless since China did not participate or even acknowledge the international dispute resolution decision. However, others rightly point out that the case served as a form of lawfare—a way of using international law and non-kinetic pressure by the Philippines to stand up against China’s aggressive and illegal activities in Philippine waters and the South China Sea more broadly. While the arbitration ruling itself may not have had enough power on its own to pressure China to drop its illegal claims or stop its actions in the South China Sea disputes, the 2016 arbitration ruling clearly rejected China’s excessive maritime claims through international law.
The 2016 arbitration ruling, which primarily ruled in favor of the Philippines, confirmed the rights of the Philippines to control its territorial waters and maritime features, as recognized by United Nations Convention on the Law of the Sea (UNCLOS), the international law of the sea. More impactful for the other disputant states—Vietnam, Malaysia, and Indonesia—was the rejection of China’s extensive nine-dash line claims for much of the South China Sea as legal. Further, the ruling provided a new interpretation on an ambiguous concept of islands in UNCLOS, setting customary law for future claims and disputes regarding islands all around the world. Thus, even though the purpose of the case was not to resolve the dispute, based on territorial and maritime claims typical of other similar cases at the International Court of Justice (ICJ), International Tribunal for the Law of the Sea (ITLOS), or arbitration panels, the legal rejection of most of China’s claims provided the tipping point for naming and shaming China for its blatant disrespect for international law and validating the legal positions of the much weaker states like the Philippines. Since the 2016 ruling, China has continued to ignore the ruling and disrespect international law. Most states in the international community recognize China’s actions and claims are illegal. This recognition of the rights of Philippines and the other disputants has provided a de facto settlement, in which China is the de facto loser.
The U.S. government under the Obama administration recognized the arbitration ruling in 2016, but they went no further than supporting the ruling as a means of supporting the rule of law. In 2019, the first Trump administration issued a statement confirming that maritime features in legally recognized Philippine waters in the South China Sea are covered by the U.S.-Philippine Mutual Defense Treaty (MDT), just three years after the ruling. This confirmation was followed by similar confirmatory statements by the Biden administration. The arbitration ruling in favor of the Philippines made it easier for the United States to make these defense commitments clear. There is strong consensus that these confirmations of U.S. defense obligations of Philippine maritime features have greatly contributed to maintaining the status quo and deterring any escalatory actions by China. Despite the continued harassment of Philippine vessels in the past few years, these actions fall short of escalatory actions by China—such as the 2012 seizure of Scarborough Shoal—that would invoke the MDT. In this sense, China has been successfully deterred from pursuing any military actions that would invoke the MDT. Importantly, the overt clarification of the U.S. position on Philippine sovereignty and U.S. defense commitments provided by both the first Trump administration and the Biden administration have provided the Philippines with the backing it has needed to stand up to China, not just legally as it did from 2013 to 2016, but also in defending Philippine fishermen and Coast Guard vessels from Chinese aggressions.
Relatedly, the United States and its allies have pursued an increasingly stronger posture against China’s claims and its aggressive actions in the South China Sea. The United States has increased freedom of navigation operations (FONOP)over the past decade, with the first Trump administration conducting the highest number of FONOPs in 2019. While the U.S. Department of Defense describes FONOPs as demonstrations of ensuring free passage, they also provide operational means of challenging and demonstrating resistance to excessive maritime claims by states like China in the South China Sea. European states are also engaging in naval operations as part of the European Union’s 2021 Indo-Pacific Cooperation Strategy to oppose China’s escalatory posture in the South China Sea and to ensure secure maritime passage for shipping, similar to the U.S. policy on FONOPs. France and Germany are regularly engaging in naval operations in the South China Sea, with more naval operations planned. The French aircraft carrier, FS Charles de Gaulle, was deployed for five months in late 2024 and spring 2025 in the Indo-Pacific, for example, participating in war game exercises with the U.S. and Japanese aircraft carriers east of the Philippines.
Along with FONOPs, the United States has broadened engagement in military exercises with the Philippines specifically though its annual exercise called Balikatan, in addition to joint military exercises with allies from within and outside the region, and in the vicinity of the South China Sea. Japan, Australia, New Zealand, South Korea, and Singapore have participated in joint military exercises from the Indo-Pacific region with the United States, disputant states, and/or each other. The United Kingdom, Germany, France, Italy, and Canada have joined the military exercises despite their lack of geographic vicinity to the Indo-Pacific or South China Sea specifically. While not officially recognized as tools of deterrence, U.S. FONOPs, other states’ naval operations, and joint military exercises pursued by the United States, the Philippines, and its allies serve as means of deterrence of China in practice.
The 2016 arbitration ruling, the clarified defense commitment by the United States to the Philippines, and the increased naval operations of the United States and its allies and partners to oppose China’s excessive claims have all provided the disputant states with increased confidence in their resolve to defend their maritime and territorial rights against China’s claims and aggressive gray zone tactics. In recent years, most of the disputants have been increasingly defending themselves, standing up to China, in a variety of ways. Not only have Indonesia, Malaysia, and the Philippines engaged in bilateral military exercises with the United States and allies, but these three disputant states have also engaged in joint multilateral military exercises as well. More telling is the disputants’ responses to Chinese aggression in recent years. Rather than retreating, vessels from Vietnam, Indonesia, and the Philippines pursuing fishing, natural resource exploration, or coast guard operations have stood their ground and directly challenged Chinese ships in their waters claimed by China. These efforts have been underappreciated in the successful deterrence of China escalating in the South China Sea and represent a significant shift in resolve by several disputant states. For several years, much of the international community has seen the Chinese gray zone actions as illegitimate and cheap shots at the weaker disputant states. These actions do not provide any legitimacy for China in terms of furthering their claims in the South China Sea. Rather, these actions only signal China’s continued refusal to recognize international law and the existing world order. The continued resolve of several disputant states against China’s illegal aggressions in the South China Sea provides a direct challenge to China’s claims, furthering the naming and shaming of China’s illegitimate activities in the disputed sea.
The current status of the South China Sea—the continued Chinese harassment of vessels and people from the disputant states—is unlikely to change. Nor is it likely that the dispute will be resolved anytime in the near future. What is also unlikely though is escalatory actions by China, especially against the Philippines, which could invoke U.S. defense obligations. There is little doubt that China wants to avoid military engagement with the United States over Philippine maritime features in the South China Sea. While the United States does not have defense commitments to other disputant states, the increased commitment by the United States, Canada, other states in the Indo-Pacific region, and states in the European Union provide increased confidence for the other disputant states. The 2016 arbitration ruling can be considered as a first major step in a series of efforts by the disputants and their supporters, including the United States and allies’ commitments to deterring Chinese escalation, and the increased resolve of the disputants to stand up to Chinese harassment. Together, all these efforts have contributed to the relatively successful deterrence of China taking control of further maritime features and other escalatory actions in the South China Sea.
