Scarborough Shoal is turning into a possible spark for naval conflict in Southeast Asia, warns a U.S. military think tank. From August 2024 to last May, researchers analysed automatic identification system data from Chinese and Philippine law enforcement vessels. In this period, China can be seen roughly tripling its coast guard patrol days.
The shoal lies about 120 nautical miles west of the Philippines. Tensions arise over its geopolitical location, inside the Filipino exclusive economic zone (EEZ), while permanently housing the Chinese coast guard since it seized control of the shoal from the Philippines in 2012,
The report—from the Asia Maritime Transparency Initiative, part of the Washington-based Center for Strategic and International Studies—points to the growing potential for conflict in the Asia-Pacific region. It states that over the past 10 months Chinese patrols have sailed east of the shoal in an attempt
aimed at intercepting Philippine ships, leading to frequent encounters between the two countries’ law enforcement vessels.
The increased harassment of Filipino shipping reflects China claiming most of the South China Sea as its own (including some atolls and reefs), using a “nine-dash line” on the map to demarcate its maritime territory. This unwelcome cartographical convention brings China’s sea border close to some of its neighbours’ coastlines.
While other Southeast Asian nations look on nervously and assert their sovereignty, the U.S. demands that the area should remain open and be treated as international waters. Both China and the Philippines conducted law enforcement patrols in the dispute area, with the latter logging 27 patrol days (compared to China’s 106).
At the heart of any future conflict here, according to the report’s authors, is position of the shoal itself. The increased activity to its east loosely matches the location of one of the hash marks found on China’s nine-dash map:
This suggests that China is using the nine-dash line rather than the territorial sea or another maritime zone from Scarborough as its imagined jurisdictional boundary.
In turn, this led to a growing numbers of airborne incidents:
In the past ten months, at least four publicly reported air interactions have occurred near Scarborough Shoal. While evocative of the regular unsafe incidents that have occurred between Chinese aircraft and those of the United States and Australia in recent years, this is a new development for the Philippines.
Many of the reefs and small patches of land in the South China Sea are uninhabitable, but thai doesn’t preclude rivalry. The Philippines keeps a handful of troops aboard warship Sierra Madre at the Second Thomas Shoal—known by Manila as Ayungin Shoal and by Beijing as Ren’ai Jiao—inside its 200-mile EEZ), despite a high-risk war of words with China over the territory in 2023.
