Bilateral talks between Tokyo and Manila over overlapping ocean claims could quietly shrink Taiwan's recognized maritime space to its territorial sea alone, an international law scholar has warned — with little Taipei can do to stop it.
Japan and the Philippines have formally launched negotiations to delimit their exclusive economic zones (EEZs) and continental shelf boundaries under the United Nations Convention on the Law of the Sea (UNCLOS). The contested waters lie east of Taiwan and overlap substantially with the 200-nautical-mile EEZ that Taiwan claims under international law. Opposition lawmakers from the Kuomintang held a press conference Tuesday calling the development a humiliating surrender of sovereign rights by the Lai administration.
Why Taiwan Has No Seat at the Table
Chou Yi (周怡), an adjunct assistant professor at the Institute of Ocean Law and Policy at National Taiwan Ocean University, told Storm Media that the bilateral process does not technically violate the treaty law principle that agreements cannot bind third parties — because neither Japan nor the Philippines recognizes Taiwan as a state.
Even under a more expansive reading that extends third-party protections to political entities, Chou noted, the delimitation framework does account for the territory under Taiwan's effective jurisdiction — namely, its territorial sea. That acknowledgment without formal contradiction, she said, makes it difficult to argue either country has breached international legal principles. Taiwanese-flagged vessels, she added, would retain freedom of navigation under customary international law.
The deeper problem, however, lies in what the agreement excludes. By drawing boundaries that treat Taiwan's EEZ claims as nonexistent, the two countries have in practical terms foreclosed Taiwan's ability to exploit natural resources in those waters and barred its agencies from conducting marine scientific research there. "That is the most troubling aspect," Chou said. The agreement, in her assessment, compresses Taiwan's effective jurisdiction to its legal minimum — the territorial sea — while disregarding the EEZ and continental shelf entitlements Taiwan asserts under international law.
Diplomatic Walls and Pragmatic Openings
Taiwan's leverage is structurally limited. Both Japan and the Philippines maintain formal diplomatic ties with Beijing and recognize the one-China principle, under which Taiwan is considered part of China. Maritime delimitation is an act of sovereign significance, Chou observed, and neither country can enter into such an agreement with Taiwan without contradicting its own stated foreign policy. "They will not, and cannot, act in a way that contradicts their own foreign policy," she said.
Given those constraints, Chou argued that pressing for a revision of the agreement is unlikely to succeed. A more productive path, she suggested, would be to move quickly on pragmatic annexes — building on existing bilateral frameworks with Japan and the Philippines to negotiate specific access rights covering fishing and scientific research. "Securing those rights first may be the more effective approach," she said.
A Joint Development Framework as a Long-Term Option
Chou also proposed a joint development mechanism with both countries as a longer-term avenue — one that would allow equitable resource access without requiring either side to resolve the underlying sovereignty dispute. International practice offers relevant precedents: Turkey, Greece, and Cyprus have managed contested maritime zones through joint development arrangements, stabilizing conditions before attempting formal delimitation.
That kind of solution, however, depends on a foundation of mutual trust and the absence of outside interference. "If external actors are working behind either side to complicate matters," Chou cautioned, "then the kind of solution that could work may never make it onto the table." （Related： Taiwan Demands a Voice in Japan-Philippines Sea Talks as China Sends Warships ｜ Latest ）
