Exclusion of Taiwan from Japan-Philippines EEZ talks fuels security risks, experts say

Japan and the Philippines have launched bilateral maritime boundary negotiations without including Taiwan, prompting warnings from security analysts who say the move damages Taiwan's sovereignty, risks a forceful Chinese response and could make waters east of Taiwan a new geopolitical flashpoint.

The absence of Taiwan

Japanese Prime Minister Sanae Takaichi and Philippine President Ferdinand Marcos Jr. met on May 28 and announced in a joint statement that the two countries would “commence formal negotiations to delimit the maritime boundary of the exclusive economic zone and the continental shelf between two countries.”

The proposed negotiations involve areas where Japanese and Philippine Exclusive Economic Zones (EEZs) overlap. The overlapping areas also significantly encroach on Taiwan's EEZ, despite Taiwan being excluded from the talks.

Liu Fu-kuo (劉復國), director of the Taiwan Center for Security Studies at National Chengchi University, told TCN that the move is highly unusual because it bypasses an affected stakeholder located between the two negotiating parties. 

He warned that the arrangement could seriously undermine the sovereignty and maritime interests of the Republic of China (ROC, Taiwan's official name).

Liu said EEZs and continental shelves involve far more than fishing rights, encompassing maritime resources, seabed development rights, and broader national interests. 

Given the extensive overlapping maritime claims among Taiwan, Japan, and the Philippines, he argued that bilateral negotiations conducted without consulting Taiwan are difficult to justify legally or under established international practice.

Juichou Richard Hu (胡瑞舟), a retired major general and deputy director of the Taiwan Center for Security Studies, expressed a similar view.

Hu told TCN that Japan and the Philippines were conducting negotiations that could affect Taiwan's maritime rights while completely excluding Taiwan from participation. 

In practical diplomatic terms, he argued, such an arrangement amounts to disregarding Taiwan's existence and inflicts significant damage on Taiwan's sovereignty, international standing, and fishing rights within its claimed EEZ.

Growing controversy

The announcement quickly drew criticism from Beijing.

Chinese Foreign Ministry spokesperson Mao Ning (毛寧) stated on May 29 that “Japan and the Philippines’ so-called maritime delimitation talks constitute a severe violation of China’s maritime rights and interests, UNCLOS and other international law and basic norms governing international relations.”

She further stated that “the so-called delimitation talks are completely illegal, null and void, and will have no effect on China’s claims to rights in the area east of the Taiwan island or exercise of China’s lawful rights.”

Taiwan's Ministry of Foreign Affairs (MOFA) issued a statement on May 31 expressing support for peaceful dialogue between Japan and the Philippines while rejecting Beijing's claims, stressing that sovereignty over Taiwan's territory and surrounding maritime areas is not subject to China's interference.

Following Beijing's protest, the China Coast Guard (CCG) announced on June 1 that a task group led by CCGS Daishan had conducted law-enforcement patrols in waters east of Taiwan. Chinese authorities explicitly linked the operation to the Japan-Philippines maritime boundary negotiations.

On June 3, Taiwan's foreign ministry issued a follow-up statement saying it had received assurances from both Tokyo and Manila that any future negotiations or agreements would not affect Taiwan's sovereign rights under international law and the law of the sea. 

The ministry reiterated that Taiwan's territorial sovereignty and maritime rights are indisputable and emphasized that Japan and the Philippines should not exclude Taiwan or undermine its interests in future negotiations.

Protecting fisheries

Meanwhile, Taiwan’s Ocean Affairs Council (OAC) Deputy Minister Chang Chung-lung (張忠龍) told media that Taiwan maintains separate fisheries agreements and law-enforcement arrangements with Japan and the Philippines. 

Chang said Taiwan would continue safeguarding its interests in accordance with existing laws and agreements. 

Chang noted that maritime boundary negotiations fall under the jurisdiction of the foreign ministry, while the OAC has already deployed large patrol vessels to key fishing grounds near Japan and the Philippines, to protect Taiwanese fishermen.

Strategic calculations

Hu viewed the decision by Japan and the Philippines to publicly launch EEZ delimitation talks at this particular moment as an action with broader strategic significance.

While the move appears likely to provoke Beijing, Hu argued that the timing may be intended to test the durability of the “constructive strategic stability” reportedly established between Washington and Beijing following the recent summit between US President Donald Trump and Chinese leader Xi Jinping (習近平).

According to Hu, Tokyo and Manila may be seeking to introduce new variables into regional security dynamics before US-China relations stabilize further. The negotiations could also serve as a test of how firmly the United States would stand by its East Asian allies under existing security treaties should tensions escalate, Hu added.

Waters east of Taiwan in the spotlight

Hu warned that Beijing is likely to respond forcefully in order to defend what it considers its sovereign rights and maritime claims.

He assessed that Chinese naval, coast guard, and air force activities could become more frequent in Taiwan's eastern offshore waters where Japan and the Philippines are set to negotiate delimitation, thereby increasing pressure on Taiwan while advancing Beijing's long-term objective of turning the waters surrounding Taiwan into a de facto internal sea.

Hu argued that Taiwan's government should more clearly and firmly assert its sovereignty and maritime rights in the affected areas. Failure to do so, he warned, could allow Beijing to strengthen its legal and political narrative regarding jurisdiction over the disputed waters.

Hu assessed that Taiwan's eastern offshore waters could become an increasingly important arena for strategic competition among multiple actors in the coming months, raising the risks of confrontation, miscalculation, and unintended escalation.

Taiwan needs action

Liu expressed a concern similar to Hu's. He argued that if Taiwan's response appears passive or hesitant, Beijing could gain both justification and initiative in claiming to defend sovereignty in the region amid the broader competition among China, Taiwan, and the US.

From the perspective of international law, Liu argued that Japan’s move to initiate negotiations is controversial. 

He noted that following World War II, the Ryukyu Islands (Okinawa) were placed under US trusteeship, and when the US and Japan signed the reversion agreement in 1972, Washington handed back only "administrative jurisdiction" rather than transferring ultimate sovereignty. 

Consequently, Liu said, whether Japan possesses the full sovereign foundation required to conduct these negotiations remains legally questionable.

According to Liu, both sides of the Taiwan Strait have historically maintained a degree of mutual understanding regarding maritime boundaries and related policies. 

Beijing has long recognized that the ROC government consistently defends its sovereignty claims, Liu said. 

However, Liu added, if Taipei appears to retreat from that position, Beijing may feel compelled to dispatch coast guard vessels to waters east of Taiwan in order to demonstrate its claims to Japan and the Philippines, further complicating the regional security environment.

Taiwan's response

Dean Karalekas, editor-at-large of Strategic Vision and an expert on international relations, told TCN that Taiwan's exclusion from the EEZ discussions presents a clear problem.

He argued that Taiwan should actively engage both Japan and the Philippines through available diplomatic channels and continue pushing for participation in regional discussions that directly affect its interests.

Liu likewise stated that Taiwan's silence could gradually erode its sovereignty and maritime rights, weakening its position in future negotiations involving maritime governance and resource development.

He argued that Taiwan should adopt a firmer and more explicit stance whenever issues of sovereignty are involved. 

Beyond reaffirming the ROC's sovereignty claims, Taipei should publicly insist that Japan and the Philippines include Taiwan in any discussions that affect overlapping maritime jurisdictions, Liu said.

"International practice shows that when sovereignty is involved, states generally defend their interests directly, actively, and forcefully," Liu said. "Taiwan should be no exception."