Opinion | China Encircles Taiwan After Japan and Philippines Draw a Maritime Border

Taiwan's Ministry of National Defense reported on the morning of June 10 that six People's Liberation Army (PLA) vessels and ten Chinese government ships remained active in waters surrounding Taiwan during the preceding 24-hour period. No PLA aircraft ventured to sea — a lull the author attributes to deteriorating weather across the island, with forecasts suggesting the conditions will persist through June 16.

In the near term, at least, Taiwan's air defenses face a reduced aerial threat.

This quiet at the surface, however, masks a month of intensifying Chinese maritime pressure that has drawn a conspicuous silence from Tokyo and Manila — the two capitals most directly implicated.

Before Beijing mobilised a national-level military-coast guard apparatus against the Japan-Philippines boundary initiative, a related episode unfolded involving a Dutch naval vessel.

The Royal Netherlands Navy frigate HNLMS De Ruyter (F804) called at Manila on May 22. The following day, it deliberately transited waters near China's Paracel Islands. Its embarked NH90 helicopter entered Paracel airspace and was warned off by the PLA's Southern Theater Command Navy.

Beijing responded immediately. It dispatched a Type 054A frigate and two Type 056A frigates — the Dali (553), Wuzhou (626), and Tianmen (631) — to intercept the Dutch vessel and escort it out of the area.

The De Ruyter proceeded to Haiphong, Vietnam for a four-day port call, departing on the afternoon of June 1.

The episode resurfaced on June 5, when PLA Eastern Theater Command spokesperson Senior Colonel Xu Chenghua stepped before cameras to announce that since May 27, the De Ruyter had "illegally intruded" into Paracel airspace before transiting the Taiwan Strait. Eastern Theater forces, he said, had conducted "full-course surveillance" throughout the vessel's passage and had "effectively responded and handled" the situation.

The statement's framing was deliberate. Beijing was not reacting to any Dutch claim about freedom of navigation. It was asserting that the Netherlands had mounted a purposeful provocation by sailing through both the South China Sea island chains and the Taiwan Strait — a harder edge than Beijing typically directs at Canadian warship transits.

The author notes that a vessel travelling between the Paracel and Spratly areas must pass south of Hainan before heading north through waters east of Taiwan. That routing, the author suspects, offered the De Ruyter an opportunity to collect electronic intelligence from PLA naval, air, and coastal installations along China's southern and eastern seaboard — a pattern analogous to US reconnaissance aircraft that routinely fly near the Chinese coastline.

Bound for RIMPAC 2026 in Hawaii, the Dutch frigate's Taiwan Strait detour was anything but incidental. It echoes the deliberate southbound transit of the Japanese destroyer JS Ikazuchi through the strait on April 17 — en route to Manila's Balikatan exercises — which itself triggered an Eastern Theater air and naval surveillance response.

Taiwan's Ministry of National Defense activity report for June 5–6 recorded 22 PLA aircraft sorties, two of which crossed the median line into central and southwestern airspace, together with eight PLA vessels and two government ships. Activity maps show fighters, drones, and what the author assesses as PLA Army Aviation WZ-10 attack helicopters operating in a band stretching from southeast of Dongshan Island, Fujian, to waters east of the Fujian-Zhejiang border.

Throughout the period, PLA aircraft mounted multiple waves of surveillance alongside the Dutch warship's transit. The Hague said nothing publicly — a silence the author reads as a deliberate choice.

When Japanese and Philippine leaders elevated their bilateral relationship to a "Comprehensive Strategic Partnership" at their Tokyo summit on May 28, their joint statement included a commitment to open negotiations on the delimitation of their respective exclusive economic zones (EEZs) and continental shelf claims.

The overlapping areas in question cover a vast expanse of ocean east of Taiwan — yet Taipei was shut out entirely.

Taiwan's Ministry of Foreign Affairs initially responded by expressing "affirmation" of the Japan-Philippines partnership, a reaction that struck many observers as tone-deaf. Though Taiwan, Japan, and the Japan-Taiwan Exchange Association subsequently clarified that bilateral boundary negotiations between third parties carry no legal binding effect on Taipei, the damage was done. Public anger across the island was swift.

Beijing's response was both swift and pre-staged. China Coast Guard (CCG) spokesperson Jiang Lüe announced that on June 1 a CCG formation led by the Daishan (CCG 2502) had commenced "law enforcement patrol operations" in waters east of "China's Taiwan Island" — framed as a necessary response to Tokyo and Manila's unilateral boundary initiative, which Beijing characterised as a serious infringement on Chinese territorial sovereignty.

The author notes that the coast guard vessels were already on station before the press release was issued: a coordinated information operation.

Data from Taiwan's Ocean Affairs Council placed the Baita (CCG 2304) 52 nautical miles east-southeast of Orchid Island at 11:00 a.m. on June 1, with the Daishan 51 nautical miles in the same direction. By the evening of June 6, the Daishan formation was still conducting a slow drift patrol at roughly two knots, approximately 64 nautical miles east of Green Island off Taiwan's eastern coast.

By June 9, according to an annotated map posted to X by National Security Council Secretary-General Wu Chao-hsieh, two coast guard vessels remained southeast of Taiwan while five ships from a Chinese maritime patrol formation tracked northward along the eastern coast.

The pattern appears to confirm a forecast the author made following coast guard activity east of Orchid Island on June 1: Beijing is moving toward a permanent joint military-coast guard posture in Taiwan's southeastern waters.

The PLA helicopter presence east of Green Island and Orchid Island predates this episode by nearly four years. Following then-US House Speaker Nancy Pelosi's visit to Taiwan in August 2022, the sea and airspace east of those islands was designated a PLA exercise zone and has since hosted a sustained naval presence of at least one warship displacing 3,000 tonnes or more.

The helicopters operating there are not land-based army aviation assets. They are ship-launched, tasked with forward surveillance of surrounding sea and air targets. The author concludes that the PLA Navy and China Coast Guard have already divided operational responsibilities in these waters.

On June 6, Xinhua reported that China's Ministry of Transport had organised the Fujian and Guangdong Maritime Safety Administrations, the East China Sea Navigation Guarantee Centre, and the East China Sea Rescue Bureau to conduct a "special maritime traffic law enforcement operation" in waters east of Taiwan — another response, Beijing said, to the Japan-Philippines boundary initiative. Some analysts characterised this as an effort to domesticate Chinese administrative jurisdiction over Taiwan-related maritime matters. The author sets aside that debate to examine what the assembled force composition actually signals.

The Ministry of Transport's selection of the Fujian and Guangdong maritime safety authorities is not incidental: the EEZ areas Japan and the Philippines seek to delimit fall squarely within those two provinces' jurisdictional purview.

The formation's core consisted of the 6,600-tonne patrol vessel Haixun 06 and the 10,000-tonne Haixun 09, with the latter serving as flagship. Both vessel classes carry deep-water survey capabilities — a detail worth noting. The East China Sea Navigation Guarantee Centre contributed the 7,500-tonne hydrographic survey vessel Haixun 08, a platform designed for long-range maritime charting operations. The author suspects the formation may have conducted hydrographic surveys along its route; whether results will be made public remains to be seen.

One factual error circulating in Chinese media deserves correction. The East China Sea Rescue Bureau's vessel Donghai Jiu 113 was widely misreported as displacing 8,000 tonnes. That figure refers to the vessel's 8,000-kilowatt towing capacity for disabled ships and offshore platforms. Its actual full-load displacement is 4,895 tonnes.

Rounding out the formation was CCG 2202, assessed by the author as having been tasked with escort and security duties. Taken together, the deployment is a visible demonstration of China's peacetime-to-wartime civil-military integration (軍民融合) doctrine applied to maritime operations.

The formation assembled at Xiamen, Fujian before June 6 and departed that day — movements assessed as having been visually detected by Taiwan. According to Taiwan's Ocean Affairs Council, the formation entered Taiwan's restricted waters 30 nautical miles southwest of Cape Eluanbi at 2:05 a.m. on June 7. By 5:30 p.m. the same day, all four Chinese government vessels had been escorted out to a position 33 nautical miles southeast of the cape.

By 11:00 a.m. on June 9, the formation was 40 nautical miles east of Pengjia Islet — 12 nautical miles outside Taiwan's restricted waters — and continuing north, with Taiwan Coast Guard vessels maintaining surveillance.

Defence Minister Wellington Koo (顧立雄) disclosed in the Legislative Yuan on June 8 that the PLA's Liaoning carrier group remained active east of the Philippines. The following day, NSC Secretary-General Wu posted an annotated diagram on X showing the carrier group operating roughly 350 to 400 kilometres east of the Philippines, alongside coast guard and maritime patrol movements east and southeast of Taiwan.

Japan's Joint Staff published a disclosure on June 1 indicating the Liaoning group had conducted operations and exercises in waters east to northeast of the Philippines from May 25 to 29 — including 170 carrier aircraft launch and recovery sorties over three consecutive days, May 26–28.

This confirmed the author's assessment that a five-vessel PLA carrier task force was simultaneously responding to the US-Philippine-Japanese "Balikatan 2026" combined exercise and applying sustained military pressure in the sea area directly implicated by the Japan-Philippines boundary statement. The author further assesses that the Liaoning group conducted simulated exercises modelling a US-Japan alliance reinforcement scenario running south from Japan toward the Philippines.

After that initial June 1 release, Japan's Joint Staff issued no further Liaoning disclosures through the author's filing deadline of June 10 at noon. The silence is telling.

As China progressively deployed coast guard and maritime patrol formations east of Taiwan between June 1 and June 6, with pressure steadily escalating, both the Philippines and Japan appeared to have made deliberate choices not to further inflame the situation. Tokyo evidently calculated that additional disclosures risked provoking further PLA deployments into the East China Sea and the waters east of the Philippines — a traditionally vital venue for US-Japan alliance maritime exercises.

On June 9, PLA Ministry of National Defense spokesperson Senior Colonel Zhang Xiaogang warned at a press conference that if Japan and the Philippines persist with their boundary initiative, they "will get what they are asking for," and that Beijing would take "resolute and forceful measures" to defend its territorial sovereignty and maritime rights.

That the warning was delivered through military channels is itself a signal: if Tokyo and Manila do not back down, the PLA is prepared to escalate further.

While public attention fixed on the Japan-Philippines boundary dispute and Beijing's national-level maritime response, the author identified a parallel development receiving far less scrutiny.

According to Chinese media reports, the PLA conducted live-fire exercises from 4:00 p.m. on June 9 to 6:00 p.m. on June 10 within a five-point polygon east of Qingdao, Shandong Province, covering approximately 2,045 square kilometres. Given the proximity of the PLA Northern Theater Command Navy's Qingdao Naval Base, the author assesses this as a live-fire training evolution for the Qingdao Destroyer Flotilla.

A second exercise, of considerably greater scope, ran from 10:00 p.m. on June 6 through midnight on June 9 in a box stretching from Zhoushan northward to the outer waters east of the Yangtze River estuary — approximately 20,689 square kilometres. An exercise of this geographic scale has been rare in recent years.

The timing matters. The exercise window coincides almost precisely with the maritime patrol formation's June 6 departure from Xiamen, the subsequent circumnavigation of Taiwan's eastern waters, and the formation's northward withdrawal beginning on June 9.

The Eastern Theater Command Navy's Zhoushan base hosts the 3rd and 6th Destroyer Flotillas. The author assesses that at minimum, Zhoushan-based destroyer flotillas and Shanghai-based frigate flotillas conducted major combined exercises, with air forces, amphibious vessels, and other service branches providing support.

The June 9 PLA Ministry of National Defense statement — timed to coincide with live exercises off eastern Zhejiang and the circumnavigation of Taiwan's eastern waters — was designed to deliver a single, unified message of military deterrence to Tokyo and Manila.

Beijing's intent is unmistakable: territorial claims and maritime rights will be defended, and the pressure will continue until Japan and the Philippines stand down. （Related： Behind the Scenes | Taiwan's Hai Kun Submarine: A Strategic Asset or Tactical Liability? ｜ Latest ）

​Original Article in Chinese​