Chinese coastguard and research vessels conducted a notable operation east of Taiwan last week, involving the interception of foreign commercial ships and detailed seabed mapping aimed at enhancing submarine operations, according to Taiwanese authorities and analysts. The exercise, lasting five days, is seen as part of Beijing’s broader strategy to extend its maritime influence in the Pacific amid rising tensions over Taiwan.
Taipei reported that a Chinese patrol boat radioed vessels from Singapore, Liberia, and Benin operating within Taiwan’s exclusive economic zone, requesting information on their origin, destination, and crew numbers—an unprecedented move in the area. Concurrently, a Chinese research vessel undertook seabed charting activities, a task critical to submarine navigation given the steep continental shelf drop-off to the east of Taiwan. This terrain is strategically important for both Chinese and U.S. submarine operations in the event of any military conflict involving Taiwan.
Chinese state media linked the operation to a recent summit between Japan and the Philippines, where the two countries agreed to delineate overlapping territorial waters. Beijing described the meeting as disregarding Chinese interests in the western Pacific and defended its maritime exercises as an assertion of “sovereign rights and jurisdiction” over the waters near Taiwan. The state social media account Yuyuan Tantian characterized the region east of Taiwan as having been incorporated into a routine “daily management grid,” signaling China's view of these waters as under its jurisdiction.
Taiwan’s government condemned the interrogation of cargo vessels as a violation of international law that undermines regional stability. Beijing’s growing use of civilian vessels—including coastguard ships, fishing boats, and research vessels described as a “militia”—is part of a deliberate effort to test Taiwan’s responses and consolidate control over maritime areas surrounding the island.
The move coincides with an expansion of China’s nuclear submarine fleet, including recent launches of the Type 095 nuclear submarine and an unorthodox “sailless” submarine spotted in a Shanghai shipyard. Experts note that seabed mapping is crucial not only for navigation but also to enhance the ability to conceal Chinese submarines and detect adversaries’, particularly in strategically sensitive waters east of Taiwan.
Thomas Shugart, a former U.S. submarine commander and naval analyst, characterized the mapping and ship interrogations as part of China’s “projection of sovereignty” and an attempt to establish a “new normal” in regional maritime conduct. Raymond Powell, director of a U.S. maritime transparency project, emphasized that control over seabed data is vital for submarine operations, especially in countering U.S. and allied attack submarines that could threaten Chinese naval forces during a conflict over Taiwan.
President Xi Jinping has reportedly directed the military to prepare for possible conflict over Taiwan by next year, despite publicly assuring the United States he has no plans for full-scale invasion. Analysts view the recent Chinese activities as components of a gradual pressure campaign combining military exercises with maritime jurisdiction assertions to strengthen Beijing’s position regarding Taiwan’s status in the Indo-Pacific region.