Inside China’s Quiet Gray-Zone Campaign Against Taiwan and the South China Sea

As gray-zone tactics steadily escalate across the Indo-Pacific, China has expanded its maritime pressure campaign beyond traditional flashpoints, pushing routine patrols directly into Taiwan’s eastern waters and testing the limits of regional deterrence.

Crossing Uncharted Waters in the East

The strategic landscape of the Taiwan Strait shifted on June 6, when four Chinese government vessels departed Xiamen, rendezvoused with four China Coast Guard ships, and sailed east to conduct patrols along Taiwan’s eastern coast. According to reports detailed by Taiwanology, this maneuver marked the first time Beijing overreached its naval jurisdiction into eastern Taiwan’s waters.

Photo: taiwanology.substack.com

The foray occurred just days after Japan and the Philippines announced a joint initiative to delimit the maritime boundary of their exclusive economic zones, a diplomatic milestone that Beijing used as an excuse to “reinforce its sovereignty”. During these operations, Chinese government vessels hailed international cargo ships—including commercial vessels belonging to Taiwan’s Evergreen—demanding details regarding their names, headings, and destinations.

By June 10, China’s official Xinhua News Agency announced the conclusion of these “special maritime law enforcement operations”, noting that a total of 198 vessels had been inspected. Shortly after, on July 4, the China Coast Guard declared that such “law enforcement operations” would become routine.

The Strategic Logic Behind the Gray Zone

The Chinese Communist Party views bringing Taiwan under its control as a ‘historic mission and an unshakable commitment’, preferring to achieve ‘reunification’ without fighting to avoid triggering a military intervention with catastrophic costs by the United States, as outlined in analysis from the Royal United Services Institute (RUSI).

Photo: rusi.org

Rather than relying solely on a high-risk amphibious invasion, Beijing leverages the “Three Warfares”—public opinion, psychological, and legal warfare—to coerce Taiwanese society, erode Taiwan’s territorial claims and sovereignty, and isolate Taiwan diplomatically. Ying-Yu Lin, an associate professor at Tamkang University, observed that while these coast guard patrols were less provocative than People’s Liberation Army military drills, the underlying political message is unmistakable: “Anything involving Taiwan is China’s internal affair.”

This calculated expansion breaches the tacit understanding maintained across the Taiwan Strait since 1949, with Chinese security forces carrying out activities in eastern Taiwanese waters for the very first time—a region entirely outside their legal purview.

Escalation Patterns and Regional Echoes

Data compiled by the CSIS Futures Lab highlights a shift in the geography of maritime pressure between 2020 and 2026, tracking how coast guard missions have gradually moved outward from the Taiwan Strait’s median line and southwestern sectors to encircle the entire island. Furthermore, Chinese authorities have regularly used the pretext of assisting stray fishing vessels since February of last year to conduct recurring bi-weekly or weekly patrols surrounding the protected waters of Dongsha.

Ray Powell, director of the SeaLight maritime transparency program and a retired U.S. Air Force colonel, warned about the long-term trajectory of these maneuvers, noting that China has begun to isolate Taiwan. Lee Chun-yee from the Institute for National Defense and Security Research pointed out the mental hazards associated with habituation, noting that gray-zone strategies reach peak peril the moment the public accepts the presence of China Coast Guard vessels as ordinary.

Similar scenarios are playing out around the Diaoyu Islands, Kinmen, Scarborough Shoal, and Second Thomas Shoal. As these synchronized pressures persist across multiple maritime domains, regional observers continue to monitor how international partners will respond to Beijing’s quiet campaign of attrition.