On June 1, China's coast guard dispatched a two-vessel formation — the Baitashan (hull number 2304) and the Daishan (hull number 2502) — to conduct what Beijing described as "law enforcement patrols" in waters southeast of Taiwan. The stated pretext was the announcement by Japan and the Philippines that they were opening negotiations to delimit their exclusive economic zones and continental shelves in waters east of Taiwan.
The patrol itself was modest in scale. What was not modest was the propaganda campaign that followed. Beijing and its state media amplified the Daishan formation's sortie far beyond what its operational scope warranted. That disproportion is a deliberate signal — one suggesting that China may be opening a new front in its long-running legal warfare campaign against Taiwan.
Beijing's Two-Track Legal Warfare Against Taiwan
China's legal warfare against Taiwan currently operates along two distinct tracks. The first is international in character: Beijing pursues expansive reinterpretations of historical instruments — most notably UN General Assembly Resolution 2758 — to conflate them with its "One China Principle," narrowing Taiwan's international space and constructing a global framework hostile to Taiwan's sovereign standing.
The second track is what analysts have called a degradation campaign: a sustained effort to reframe the Republic of China government as a subordinate local authority, stripping it of the legal standing that only a central government possesses. Beijing has stated its goals plainly — "resolutely combating Taiwan independence separatism" and "suppressing external interference."
The starting point of this degradation campaign can be traced to June 13, 2022, when then-Foreign Ministry spokesperson Wang Wenbin declared at a regular press briefing that China holds "sovereignty, sovereign rights, and jurisdiction" over the entire Taiwan Strait, and that the strait's waters constitute successively China's internal waters, territorial sea, contiguous zone, and exclusive economic zone under UNCLOS and Chinese domestic law.
That statement became Beijing's authoritative formula for legal warfare over the Taiwan Strait. What followed was its systematic translation into physical facts at sea.
Kinmen and Pratas: A Pattern of Calculated Encroachment
From June 2022 onward, Beijing unilaterally abandoned the informal median line understanding that had governed cross-strait military behavior for decades. PLA aircraft, naval vessels, and coast guard ships began crossing the centerline with increasing regularity. Public vessels were sent to patrol Taiwan's restricted waters around Kinmen on a routine basis. The cumulative purpose is clear: by gradually displacing Taiwan's effective administration over these waters, Beijing aims to close the evidentiary gap in its claim to jurisdiction over virtually the entire Taiwan Strait. At the same time, by refusing to recognize Taiwan's self-declared restricted maritime zones, territorial seas, and contiguous zones — legal instruments that only a central government has the authority to issue — Beijing signals that Taiwan is not a sovereign state but an administrative region without the standing to legislate.
The pattern around Kinmen is illustrative. Following the February 14, 2024 incident involving an unregistered mainland fishing vessel — a flashpoint in cross-strait maritime tensions — China Coast Guard ships began entering Kinmen's restricted zones on a regularized schedule. The pattern has stabilized at roughly four incursions per month, four vessels per incursion, deployed in single-ship, paired, or four-vessel formations as circumstances dictate. From February 2024 through May 28 of this year, there have been 117 recorded sorties: 52 in 2024, 46 in 2025, and 19 so far in 2026.
Beijing has since extended this template to the waters around Pratas Island (Dongsha). From February 2025 onward, large flotillas of mainland fishing vessels began entering Taiwan's restricted zone around Pratas — an area equivalent to the island's contiguous zone, covering 12 to 24 nautical miles. Coast guard vessels occasionally accompanied them, interfering with Taiwan Coast Guard enforcement operations. In some instances, mainland fishing boats launched small craft that penetrated even the innermost prohibited zone, equivalent to Pratas's territorial waters.
The behavioral shift among coast guard vessels is analytically significant. Before February 2025, occasional transits of the 24-nautical-mile restricted zone could be assessed, based on heading, speed, and duration, as incidental passage. After that date, a new pattern emerged: one or two vessels began conducting irregular, repetitive back-and-forth movements along the edge of the zone, clearly probing for entry opportunities. This is no longer incidental navigation. It is a calculated gray-zone operation with rhythm, strategy, and purpose. From February 2025 through May 28 of this year, 12 individual coast guard ships — comprising 39 vessel-sorties — were monitored by Taiwan's coast guard attempting to breach the Pratas restricted zone: 33 sorties in 2025, and 6 so far this year.
Beijing May Be Pushing Japan and the Philippines to Bypass Taiwan
Beijing's disproportionate response to the Japan-Philippines delimitation announcement is only partly explained by the strategic optics of Tokyo and Manila presenting a united front. The more consequential possibility is that Beijing intends to use this episode as a pretext to begin regularized coast guard patrols in waters that fall within Taiwan's exclusive economic zone under UNCLOS but which Japan and the Philippines have included within their delimitation talks. If Beijing follows the Kinmen template — building a routine presence through repeated, sustained incursions — it would be extending its legal warfare campaign from the median line and Taiwan's outlying island restricted zones all the way to Taiwan's eastern EEZ.
The intent behind this extension is not merely territorial. By establishing a de facto presence in Taiwan's eastern EEZ, Beijing would be accumulating new evidentiary support for its claim that Taiwan is an inseparable part of China. Taiwan Affairs Office spokesperson Chu Feng-lien reinforced that framing on June 3, stating that the maritime zones Japan and the Philippines proposed to delimit lie east of "China's Taiwan Island" and "severely infringe upon China's maritime rights and interests."
Even more significant was Foreign Ministry spokesperson Mao Ning's statement at the June 2 press briefing. Beyond reiterating claims she had made on May 29, Mao introduced new language: that any delimitation negotiations concerning waters east of Taiwan "must involve China." Under UNCLOS, she argued, Beijing — not Taipei — holds exclusive legal standing to participate in maritime boundary talks in those waters.
This is not procedural boilerplate. It is a direct assertion that Beijing possesses the sovereign standing to participate in any maritime delimitation talks involving Taiwan's eastern waters — while Taipei does not. The implication is that China may use sustained diplomatic pressure, and potentially coercive action at sea, to push Japan and the Philippines into negotiating with Beijing on matters that would otherwise involve Taiwan: rules of encounter for coast guard vessels of all parties, fisheries management arrangements, and operational rules governing vessels from mainland China, Taiwan, Japan, and the Philippines in these waters. Were Tokyo and Manila to accede — even in a narrow, practical sense — Beijing would acquire new evidentiary grounds for its jurisdictional claims over Taiwan's eastern waters. More broadly, it would transform what has been a bilateral legal degradation campaign against Taiwan into something approaching a multilateral international campaign against Taiwan's legal personality as a state.
Taiwan Must Act Before Beijing Sets a New Precedent
Taipei cannot afford to treat this as a manageable irritant. The immediate priority is to accelerate consultations with both Tokyo and Manila, using as a template the April 10, 2013 fisheries agreement between the Association of East Asian Relations and the Japan Interchange Association, and the November 5, 2015 Taiwan-Philippines Fisheries Law Enforcement Cooperation Agreement. Formal written arrangements covering maritime rights, fisheries access, and enforcement protocols must be concluded before Beijing can exploit their absence to assert its own jurisdiction by default.
The legal warfare Beijing is waging against Taiwan is not a series of disconnected provocations. It is a systematic, long-term campaign to redefine Taiwan's status under international law through the accumulation of facts at sea. Every unremedied incursion, every uncontested patrol, and every bilateral negotiation that excludes Taipei becomes another brick in that structure. Taiwan's government — and its partners in Tokyo and Manila — must recognize what is being built before it becomes too late to stop it.
*The author is an associate research fellow at the Division of Defense Strategy and Resources, Institute for National Defense and Security Research. （Related： Taiwan Demands a Voice in Japan-Philippines Sea Talks as China Sends Warships ｜ Latest ）
