Broken Chain

It was an unexpected rendezvous.

On June 6, four large Chinese government vessels departed from Xiamen for waters east of Taiwan. Their mission was to protest Japan–Philippines negotiations to delimit their overlapping exclusive economic zones (EEZs), which Beijing said infringed upon “China's national rights and interests.”

As they passed southwest of Cape Eluanbi, they radioed the Singapore-flagged Evergreen Marine cargo ship EVER VISTA, requesting its name, course and destination. The crew answered each question in Chinese.

For Evergreen, a shipping giant with around 200 vessels at sea at any given time, the exchange was too minor to warrant reporting to headquarters. Radio inquiries from government vessels are not uncommon at sea and are generally left to the captain to handle.

“As long as they are not ordered to stop or submit to boarding and inspection, most crews will give a brief response,” a senior executive at a shipping company said. “After all, they're dealing with state authorities, and no one wants to offend either side.”

Evergreen never imagined that this seemingly routine response would strike a nerve with Taiwan's authorities. Taiwan Coast Guard Administration disclosed the incident to foreign media, explicitly naming Evergreen and emphasizing that the radio response had come from a mainland Chinese crew member.

Little did Evergreen know that it had become part of a historic moment for the First Island Chain.

Chinese government vessels appeared in waters around Taiwan in June. Taiwan Coast Guard Administration's CHANGBIN (CG611) monitored the movements of HAI XUN 06. (Source: Taiwan Coast Guard Administration)

On June 11, the Chinese Communist Party mouthpiece People’s Daily framed the “law enforcement operation” as a “necessary action in response to Japan and the Philippines unilaterally announcing the start of maritime boundary negotiations in the waters east of China’s Taiwan island, gravely infringing upon China’s territorial sovereignty and maritime rights and interests.”

On July 4, the China Coast Guard went further, announcing that law enforcement in the eastern waters would become routine in order to “resolutely safeguard the nation’s territory”—an attempt to establish a new normal along the First Island Chain.

In Beijing's narrative, Taiwan is part of China—it is only natural for Chinese government vessels to enforce Chinese law in what it considers Chinese waters.

China Breaks a Longstanding Cross-Strait Tacit Agreement

This time, Beijing did not respond to the delimitation with its typical People’s Liberation Army (PLA) military exercises. Deploying the PLA, Lin explained, could alarm neighboring countries and provide a pretext for intervention. Law enforcement by government vessels offers a lower-intensity means of asserting sovereignty, with less risk of confrontation. This is also why the coast guard is especially active in disputed waters, including the Diaoyutai Islands (known as Diaoyu in China and Senkaku in Japan), Scarborough Shoal and Second Thomas Shoal in the South China Sea.

"The coast guard is a domestic agency, so its involvement signals that Taiwan is being handled as an internal matter," Lin said.

In footage later released by China, a rescue vessel operating off Hualien and Taitung was shown holding a ceremony to raise the PRC flag on its deck—a gesture carrying a strong assertion of sovereignty.

Beijing has never publicly denied the Republic of China's (ROC) exercise of jurisdiction over Taiwan, Penghu, Kinmen and Matsu since 1949. It even warned Chinese vessels to stay out of "disputed waters" and refrained from encroaching on areas under Taiwan's jurisdiction. That tacit understanding no longer exists.

Though China Coast Guard vessels had previously entered Kinmen's prohibited and restricted waters several times, they had not taken law enforcement action. The 2024 boarding and inspection of a Kinmen tour boat occurred in waters closer to Xiamen. This June, however, Chinese government vessels carried out law enforcement operations in waters where they had never previously exercised jurisdiction—and they even targeted foreign commercial ships.

On June 11, Yuyuan Tantian, a social media account affiliated with China Central Television (CCTV), put the claim even more bluntly: "In the future, the term 'Taiwan Strait' will gradually disappear. ... The waters east of Taiwan Island are our near seas. These are waters in which we maintain a presence, exercise jurisdiction and govern."

China’s Gray-Zone Operations Have Encircled Taiwan

Shifts in Chinese government vessel activity hotspots in recent years

Activity intensity Low High Taiwan ADIZ Prohibited waters Restricted waters

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Note: Data for 2026 are through July 6. Hotspots were statistically estimated based on the observed positions of Chinese government vessels. Source: Jose M. Macias, CSIS Futures Lab, Global Fishing Watch, Maritime Port Bureau Vessel Traffic Service System, Taiwan Coast Guard Administration, Ministry of National Defense, Natural Earth

The China Coast Guard had spent years preparing to “erase the line.”

CommonWealth Magazine partnered with the Futures Lab at the Center for Strategic and International Studies (CSIS), a leading U.S. think tank, to analyze the distribution of China Coast Guard activity around Taiwan’s main island from 2020 through the first half of 2026, using an analytical model developed by researcher Jose M. Macias.

Beginning in 2020, the China Coast Guard first stepped up its activity in waters southwest of Taiwan. "This is strategically vital territory—the first step in breaking through the First Island Chain," Lin explained. Its operations subsequently expanded toward the Taiwan Strait median line, with the move to waters off Taiwan's east coast marking the latest phase.

Chinese Government Vessels Enter Waters off Itu Aba for the First Time as Dongsha Islands Emerge as a New Hotspot

Dates of reported Chinese government vessel sightings around Taiwan since 2024

Note: Data are through July 21. Counts are based on Coast Guard Administration announcements by date and area. Multiple incidents in the same area on the same day are counted once; vessel type and vessel count are not distinguished. Source: Taiwan Coast Guard Administration

Which waters under the ROC’s jurisdiction have faced the greatest pressure?

Kinmen continues to bear the brunt, while Dongsha is gradually emerging as a new, recurring hotspot.

Since February 2025, Chinese government vessels have begun making incursions around Dongsha on the pretext of escorting fishing boats operating across the boundary. They now regularly patrol around the area’s prohibited and restricted waters roughly every one to two weeks.

The number of days on which Chinese government vessels were active in waters east of Taiwan rose from just two in all of 2024 to nine in the first half of this year.

Chinese government vessels also entered waters around Itu Aba in the South China Sea for the first time.

“China is claiming everything within its U-shaped line in the South China Sea,” said Chung Chieh (揭仲), a research fellow at the Institute for National Defense and Security Research (INDSR). He suggested that this may help explain Beijing's concerns. “After Taiwan's Ministry of Foreign Affairs voiced support for the Japan-Philippines negotiations, China may have begun to worry that the DPP government could make concessions on its South China Sea claims in an effort to garner international support.”

On July 20, 2026, China Coast Guard and Philippine Navy personnel clashed near the Second Thomas Shoal outpost. The dispute then spilled over to the ASEAN Foreign Ministers' Meeting in Manila, where the foreign ministers exchanged sharp protests. （Ⓒ X @ChinaMilBugle）

In fact, Chinese government vessels have been operating throughout the First Island Chain in the name of "law enforcement" for more than a decade. Under international law, Beijing is seeking effective control over the islands, reefs and waters it claims, to strengthen the legal basis for its claims.

"International law tends to favor the party that exercises effective control," said Huang-chih Chiang (姜皇池), a professor of international law at National Taiwan University. Whether in the Diaoyutai Islands or the South China Sea, China is seeking to establish effective control in an effort to create a fait accompli.

With negotiations over competing claims at an impasse, the contest ultimately comes down to power. Japan is seeking to preserve the effective control it has maintained over the Diaoyutai Islands for more than a century, while the Philippines is trying to challenge China's control over Scarborough Shoal and Second Thomas Shoal.

Note: Data are through July 17, 2026. Source: Global Fishing Watch, Taiwan Coast Guard Administration, West Philippine Sea Transparency Initiative, Japan Coast Guard, Ministry of National Defense, Natural Earth.

On the map, these islands are thousands of kilometers apart. Yet the playbooks behind the operations are strikingly similar.

After comparing data from Kinmen and the Diaoyutai Islands, Yun-hu Yeh (葉雲虎), chair of the Department of Maritime Police at Central Police University, found similarities in the number of vessels, the frequency of patrols and the way they loitered in both areas. The findings suggest that Beijing's operations across different waters may follow the same standard operating procedures.

Renato Cruz De Castro, a professor at De La Salle University, said China's pressure campaign against the Philippines has gone a step further. In recent years, Beijing has deployed what he calls the "three dragons" — the China Coast Guard, the maritime militia and the PLA Navy — in a coordinated effort.

Since late 2024, international intelligence has detected Chinese vessels operating in waters east of the Philippines and even as far as Guam.

Taiwan's Delicate Position Between China, Japan and the Philippines

The ROC also claims sovereignty over the Diaoyutai Islands and islands in the South China Sea. During the Ma Ying-jeou administration, Taiwan set aside sovereignty disputes while maintaining its claims, reaching separate agreements with Japan and the Philippines to address fishing rights and coast guard coordination.

Kuan-hsiung Wang (王冠雄), a professor of international law at National Taiwan Normal University, argued that as China, Japan and the Philippines compete for control over EEZs that Taiwan also claims, Taipei cannot simply remain on the sidelines and call for restraint. "Otherwise, no matter how the disputes are resolved, Taiwan will be left in an awkward position," he said.

This time, Chinese government vessels directly radioed international commercial ships and demanded that they report information. From the perspective of the U.S. and its allies, the issue extends beyond cross-strait sovereignty disputes to the freedom of navigation in the Indo-Pacific.

The Taiwan Strait is a global security issue. Experts gathered at an international forum hosted by Taiwan's Ocean Affairs Council to discuss regional security challenges. (Photo by Chien-tung Wang)

When U.S. Secretary of State Marco Rubio visited the Philippines in late July, he told reporters: "We’re never going to accept that international waterways are somehow under the control of other countries."

The Royal United Services Institute (RUSI), a British think tank, has described the China Coast Guard's activities as part of Beijing's effort to reshape the regional and international maritime order.

The representative offices of the United Kingdom, France and Germany in Taiwan issued their first-ever joint statement on a Taiwan-related issue, warning that China's "new activities" in waters east of Taiwan threaten regional stability, freedom of navigation and security. They also reaffirmed their opposition to any unilateral attempt to change the status quo.

More Dangerous Than Military Drills

The threat goes beyond challenges to Taiwan's jurisdiction and the cross-strait status quo. Taiwan also faces the prospect of a "quarantine."

Unlike a military blockade, in which the PLA prevents all vessels from entering or leaving Taiwan, Lin explained, a quarantine allows Beijing to decide who may enter or leave. It would prevent Taiwan's government from protecting vessels in waters under its jurisdiction, thereby changing the status quo.

Taiwan's Pacific coast forms a key link in the First Island Chain, making it a new hotspot in the region's maritime contest. (Photo by Chien-ying Chiu)

Ray Powell, director of Stanford University's SeaLight project, warned that China's quarantine strategy is already taking shape.

"They wouldn't come out all at once and announce, 'We're quarantining Taiwan,'" Powell said. "Today, they patrol the waters and challenge commercial ships over the radio. Tomorrow, they could stop and inspect them, then cite some kind of 'violation' to reroute a ship to the mainland—or even turn it around."

"The most dangerous moment in a gray-zone campaign is when people come to accept the presence and law enforcement activities of China Coast Guard vessels as the new normal," said Jyun-yi Lee (李俊毅), a research fellow at INDSR. By then, the order in waters around Taiwan could be rewritten without a single shot being fired. “It won't matter how capable our military is—it will have no role to play.”

That is why every protest from allies and every Coast Guard operation to drive Chinese vessels away matters. What is ultimately at stake is how the world perceives who has jurisdiction over these waters—and what constitutes the status quo.

Wu-yueh Chang (張五岳), director of the Center for Cross-Strait Relations at Tamkang University and a longtime scholar of Beijing's Taiwan policy, warned that if China Coast Guard operations escalate to the point of effectively quarantining Taiwan, "It would be Taiwan's greatest crisis since 1949."