TAIPEI (Taiwan News) — Chinese research vessels have been sailing near or directly over critical undersea communications cables around Taiwan in an evolving gray zone campaign that is reshaping the maritime and information battlespace.
Beijing is mapping the seabed, monitoring cable routes and pre-positioning capabilities to create a threat in the event of a conflict — all while remaining below the threshold of open warfare, according to a Sky News investigation, conducted with the Center for Strategic and International Studies (CSIS) that was published Saturday.
The report identifies a new dimension in Beijing’s coercion strategy. While earlier gray zone tactics focused on air incursions, coast guard patrols and diplomatic pressure, the campaign now increasingly targets the information and undersea domains that sustain Taiwan’s economy and its links to allies.
The investigation tracked multiple Chinese research ships operating around the country over the summer and found them repeatedly transiting key cable routes on the seabed. It concluded this represents a new phase in Beijing’s effort to shape the future battlespace around Taiwan. This includes air, land, sea, space, cyberspace and the information environment
The undersea cable network — insulated fiber-optic lines on the ocean floor — carries most of the world’s internet traffic. The nation’s connection to the rest of the world relies on a small number of these cables, making them a strategic vulnerability, Sky reported.
In 2025, a Chinese national who captained a ship was sentenced to three years in prison for damaging an undersea cable linking Taiwan proper with the Penghu islands, underscoring the fragility of the infrastructure. Even so, China has dismissed claims that its vessels are deliberately targeting undersea cables.
The defense ministry has noted an upward trend in the number of Chinese naval and coast guard movements during military drills. Additionally, Taipei tracked more than 110 Chinese military and coast guard ships operating along the First Island Chain from Taiwan to Borneo in July, according to a Reuters report.
Analysts say the integration of unmanned systems, expanded coast guard law-enforcement operations and persistent naval patrols are tightening what they describe as a maritime “noose” around Taiwan.