CHINA is expanding its maritime presence east of Taiwan following closer cooperation between Japan and the Philippines, in an apparent effort to establish greater authority over waters in the Philippine Sea, according to the Asia Maritime Transparency Initiative (AMTI).
The Washington-based maritime security research group said the "unprecedented" Chinese operations, including sustained law-enforcement patrols, maritime surveys near Taiwan and the questioning of nearly 200 commercial vessels, followed a May agreement between Tokyo and Manila to negotiate a maritime boundary.
"The scale and character of China's response suggest that these operations are not just about sending a signal to Tokyo and Manila," Bloomberg reported AMTI saying in a report released on Aug 19.
It said Beijing could be seeking to alter the status quo by establishing a semi-permanent presence east of Taiwan and asserting authority over the waters.
The activity could also normalise a Chinese presence around Taiwan while allowing Beijing to test tactics that could prove relevant in a future quarantine or blockade of the island, AMTI warned.
The operations represent an escalation in tensions with both Tokyo and Manila and mirror the so-called grey-zone tactics China has increasingly employed in its maritime disputes in the South China Sea.
According to AMTI, Chinese law-enforcement activity between June and August was concentrated east of Taiwan, primarily involving two vessels, in an area where Japan and the Philippines have overlapping maritime claims.
Virtually no Chinese law-enforcement deployment was observed in the area during the five months before Japan and the Philippines announced their maritime delimitation talks.
China also issued a legal warning against the two countries in July, saying their maritime boundary discussions "constitute a severe provocation against the One-China principle".
The development comes as Japan and the Philippines deepen their military and security cooperation. The two countries agreed this year to elevate their relationship and establish a series of defence talks, amid growing regional tensions.
Japan and the Philippines have in recent months also adopted more assertive positions on Taiwan, raising concerns in Beijing over their potential involvement in any conflict involving the self-governing island.
China disputes Japan's control of the Senkaku Islands, which Beijing calls the Diaoyu Islands, in the East China Sea.
With the Philippines, Beijing contests sovereignty and maritime rights across parts of the South China Sea, including Scarborough Shoal and the Spratly Islands, where several other claimant states, including Vietnam, are strengthening their defences as China's military capabilities expand.
"The operations in the Philippine Sea suggest Beijing seeks broad and unprecedented jurisdiction over what it calls its 'near seas,'" AMTI said. - August 20, 2026
