In the image
Troops aboard the BRP Sierra Madre raising the Philippine flag [Armed Forces of the Philippines]
In July 2016, the Permanent Court of Arbitration in The Hague ruled against the People’s Republic of China’s claims to historical rights—marked by the so-called “nine-dash line”—over waters disputed with the Philippines in the South China Sea. Beijing did not accept the international ruling and has maintained its assertive presence in the disputed waters, intensifying its harassment of Philippine troops and fishermen. Ten years after the ruling, what is Manila’s stance, and what support does it receive from its allies?
On January 22, 2013, the Republic of the Philippines initiated arbitration proceedings against the People’s Republic of China regarding its use of “historical rights” as a basis for maritime claims. Specifically, it challenged China’s nine-dash line, the status of certain maritime features in the region, and the lawfulness of specific Chinese actions that allegedly violated the United Nations Convention on the Law of the Sea (UNCLOS). The proceedings lasted three and a half years, and the case records contain a vast collection of legal briefs, expert reports on environmental safety, and procedural orders, all culminating in the final award issued on July 12, 2016.
The Permanent Court of Arbitration’s (PCA) landmark ruling formally rejected China’s expansive claims to much of the South China Sea and concluded that there was no evidence that China had historically exercised exclusive control over the waterway. In other words, the Nine-Dash Line was effectively delegitimized and overruled. Now, ten years later, how has this all played out? How did the international political system react to this ruling, and in what ways has this issue evolved since?
What is at stake
A key element—and a good place to start—is to consider what is at stake in this issue. Control of this waterway provides crucial access to the Strait of Malacca, a chokepoint through which nearly 40% of global trade and 80% of China’s oil imports pass. The maritime region also contains an estimated 190 trillion cubic feet of natural gas and 11 billion barrels of oil—resources that could be crucial for Philippine energy security as the Malampaya gas field is depleted. Furthermore, among Philippine fishermen and environmental conservation experts, Chinese ships are notorious for exploiting the rich marine life and coral reefs that also inhabit the area.
The sea is roughly the size of India and contains hundreds of islands and islets. It boasts some of the highest levels of marine biodiversity on Earth, with 571 known species of reef corals that are crucial to the fishing economies of neighboring countries. Chinese giant clam harvesting and the construction of artificial islands are among the ways in which this destruction and exploitation are carried out. All things considered, it is no surprise that both global and regional powers are eager to gain influence over the area, even if it means disregarding international law.
Reactions from Beijing and Manila
In light of this, a key factor in this dispute is the stance China took during the years the PCA proceedings were active. Throughout those three and a half years, China adopted a “position of non-acceptance and non-participation in the proceedings,” refusing to cooperate and recognize the Court’s authority. This was the first problem. The ‘Global Times,’ a Chinese daily tabloid under the state-run ‘People’s Daily,’ noted that the decision was“null and void,” publishing a series of articles claiming the tribunal’s lack of jurisdiction, reiterating that the ruling is illegal, and noting how the country even saw a surge in patriotism following it. The Communist Party of China (CPC), of course, aligned with this rhetoric, with President Xi Jinping stating that “China’s territorial sovereignty and maritime interests in the South China Sea will, under no circumstances, be affected by the award.”
Adding fuel to the fire, former Philippine President Rodrigo Duterte—known for his“war on drugs”and close ties with China—had just begun his term at the time and expressed his reluctance to comply with the ruling, infamously dismissing it as“scrap paper.” His reasoning was based on the belief that good relations with China would bring economic benefits and that confronting Beijing would lead to repercussions. Critics both at home and abroad have questioned this approach, pointing out that promised Chinese investments in the Philippines never materialized, and that the country, at the same time, saw an increase in government corruption under Duterte’s administration. It is as if Philippine maritime sovereignty was traded away for private gain. Under current President Marcos Jr., corruption continues to burden the country, with hundreds of billions of Philippine pesos lost every year as a result.
Disputed area
Returning to the key issue, the aftermath of the 2016 PCA ruling saw an increase in the Chinese presence in the disputed area. What was formerly labeled as “visits” or “harassments” by Chinese ships evolved into a permanent and integrated opposing force. Chinese vessels include a mix of People’s Liberation Army Navy (PLAN) warships, China Coast Guard (CCG) vessels, and maritime militia (armed fishing vessels) that are strategically deployed across key reefs, islands, and passage points throughout the maritime area. As of March 2026, over 60 Chinese PLAN and CCG warships are present in the West Philippine Sea, accompanied by some 241 maritime militia vessels known as the “Spratly Backbone Fishing Fleet.”
The geographical location of the key reefs and islands in dispute favors Manila. For instance, Mischief Reef is 129 nautical miles (239 km) from the Philippine province of Palawan, while it is about 600 nautical miles (1,111 km) from the nearest Chinese coastline in Hainan. Similarly, the Scarborough Shoal lies 124 nautical miles (230 km) from the Philippine province of Zambales and 472 nautical miles (874 km) from mainland China. It is important to keep in mind when assessing such figures that Article 57 (20) of UNCLOS states that a nation’s “exclusive economic zone [EEZ] shall not extend beyond 200 nautical miles” (~370 kilometers) from the baselines from which the breadth of the territorial sea is measured—in other words, its shores. According to international law, then, these disputed islands lie well within the Philippines’ EEZ, and in theory, would even extend it by the additional 200 nautical miles required by Article 57. Figures like these are what establish the contestability of the nine-dash line, and although it was “erased” from legal documents, it continues to be reinforced by ships at sea.
‘Grey zone’ tactics
To assert its presence in the region, China employs “gray zone” tactics: actions that are aggressive enough to seize territory, yet calculated to remain just below the threshold of actual wartime tactics. This includes intentionally ramming ships or using water cannons against Philippine fishing or naval vessels. The growing presence of Chinese vessels poses the risk of such skirmishes becoming normalized in the area—the possibility that the international community will quietly accept these dangerous encounters as standard tools of statecraft. This, of course, threatens the safety of fishermen and maritime workers, Philippine sovereignty, and the rules-based international system.
An epicenter of these “gray zone” tactics is Second Thomas Shoal, known as “Ayungin Shoal” by locals. It is located roughly 105 nautical miles (~190 km) west of the Philippine province of Palawan and is a key point of contention due to the BRP Sierra Madre. What was once a U.S. battleship during both World War II and the Vietnam War was integrated into the Philippine Navy after it transported roughly 3,000 refugees from Vietnam to the Philippines in 1975. Today, though rusting away, the BRP Sierra Madre is permanently grounded on Second Thomas Shoal, serving as a unique base from which the Philippines aims to protect its maritime sovereignty in the face of harassment and interception by supply vessels, as well as intentional ship ramming.
Current Philippine administration
In contrast to former President Rodrigo Duterte’s rather passive approach to the issue, current President Ferdinand Marcos Jr. has adopted a more direct and assertive strategy known as the “Assertive Transparency Initiative.” It is an information campaign that calls for the publication of videos and images to expose Chinese “gray zone” tactics and false narratives, debunking disinformation to more clearly demonstrate the severity of the situation to the world. This assertive stance coincides with the Philippines’ 2026 ASEAN Chairmanship, during which Manila has placed the finalization of a legally binding Code of Conduct (COC) at the top of the regional diary, aiming to establish clear rules for maritime engagement in the area.
At sea, the Philippines has also engaged in multilateral maritime cooperative activities with U.S. and Japanese forces. These joint patrols and exercises also involve Australia and, most recently, Canada, serving as a concrete demonstration of the Philippines’ determination to maintain a presence in its own Exclusive Economic Zone. Conducting these operations with high-profile allies is a way to demonstrate that the 2016 PCA ruling is supported by key players in the international system, and although the Marcos administration is taking a step in the right direction, China’s persistent determination to dominate the region suggests that this is only the beginning of a long-lasting struggle for actual maritime control.
It must also be considered that, with both escalating tensions and the increasingly frequent use of gray-zone tactics, the dangerous possibility of a future miscalculation continues to grow. For instance, if a future incident involving a Chinese ship ramming or water cannon harassment is miscalculated and results in the death of a Filipino serviceman or Navy officer, the 1951 U.S.-Philippine Mutual Defense Treaty could be triggered. Without a doubt, this would result in a massive escalation of the issue—possibly leading the three countries to war, with enormous international consequences given their vast influence over world politics.
The coming decade
Ten years after the PCA ruling, the South China Sea dispute remains a persistent focal point of international tensions and discussion. While the Marcos administration’s “Assertive Transparency” policy and strengthened alliances have continued to bring the issue to the international stage, the burden of maintaining a presence in the disputed area to protect maritime sovereignty remains heavy.
Whether through a breakthrough in the ASEAN Code of Conduct or a continued stalemate at sea, the next decade will be crucial in determining whether international law serves as a true shield for smaller nations or whether military might continues to dominate as the primary mechanism for resolving territorial disputes. With Manila and its allies moving toward a more integrated defense posture, the coming years will reveal whether the 2016 ruling can be transformed from a legal declaration into a sustainable regional reality.