Japan warship in Taiwan Strait signals free passage rights: Academic

Taipei, April 18 (CNA) The transit of a Japan Maritime Self-Defense Force (JMSDF) warship through the Taiwan Strait on Friday reflected Tokyo's reaffirmation of its right to free passage through the international waterway, an academic has said.

The passage by the destroyer JS Ikazuchi, from 4:02 a.m. to 5:50 p.m., was reported by the Chinese People's Liberation Army's (PLA) Eastern Theater Command on Friday night. The command said it had dispatched naval and air forces to shadow the Japanese vessel.

China's Ministry of Foreign Affairs said Friday it had "strongly protested" the transit with Tokyo.

Taiwan's Ministry of National Defense declined to comment, saying only that it was closely monitoring the surrounding waters and airspace using joint intelligence, surveillance and reconnaissance systems.

It was the fourth Taiwan Strait transit by a Japanese warship, following a September 2024 passage alongside Australian and New Zealand vessels and solo transits in February and June 2025.

Jason Kuo (郭銘傑), an associate professor of political science at National Taiwan University, said the ship's passage showed Tokyo exercising its right to freedom of navigation on the high seas, as stipulated in the United Nations Convention on the Law of the Sea.

It also signaled a shift from historically United States-led freedom of navigation operations to broader international participation in Taiwan Strait affairs, Kuo said in a social media post.

In doing so, what has traditionally been a strategic arena dominated by China and the U.S. is becoming more multilateral, he said, a situation that will test stakeholders' ability to maintain strategic signaling in the strait while avoiding escalation and miscalculation.

In a statement issued Saturday afternoon, the PLA's Eastern Theater Command said it had dispatched naval and air assets to conduct "joint readiness patrols" in the East China Sea, without specifying the scope of the drills.

The command described the activity as a routine annual exercise aimed at testing joint operational capabilities.