Asia Defense | Security | East Asia

Japan’s Frigate Diplomacy — and What It Could Mean for Taiwan

Can Japan become a second major democratic partner for Taiwan’s defense industry?

The JS Mogami, first ship of the Mogami class, at sea on June 10, 2022.

In mid-April 2026, Taiwanese media reported that the Republic of China (ROC) Navy is evaluating Japan’s upgraded Mogami-class frigate, known in the Japan Maritime Self-Defense Force as the New FFM, as a candidate for its planned 6,000-ton next-generation surface combatant. The reporting cited unnamed sources and suggested that Tokyo had quietly relaxed restrictions on transferring warship blueprints to Taipei. 

Japanese officials have not confirmed any of this. Even so, the report is significant. Five years ago, the policy possibility it describes did not exist.

Taiwan’s interest in the design is easy to understand. Of roughly 25 major surface combatants in Taiwan’s navy, 15 have served more than 25 years; the Chi Yang-class frigates are now over 50 years old. Taipei is investing in indigenous corvettes, a modernized Kang Ding fleet, and a domestic submarine program (the lead boat, Hai Kun, conducted sea trials in 2025), but a single supplier base, even one supplemented by the United States, will not close every gap. The harder question is whether Japan can become a second major democratic partner without breaking its own legal and political architecture in the process.

That architecture has shifted more in the past three years than in the previous three decades. In December 2023, the Kishida Cabinet revised Japan’s 2014 Three Principles on Transfer of Defense Equipment and Technology, permitting limited exports of lethal equipment in five operational categories (rescue, transport, warning, surveillance, and minesweeping) and allowing the re-export of licensed defense products to their country of origin. In March 2024, a second Cabinet decision authorized the export of the Global Combat Air Program fighter, co-developed with Britain and Italy, to countries holding defense equipment transfer agreements with Japan. In February 2026, the Liberal Democratic Party (LDP) moved to abolish the five-category framework and replace it with a simpler weapons and non-weapons classification. The Takaichi Cabinet formally approved a broader liberalization in April.

The political environment around these reforms also looks different. Komeito, the LDP’s longtime junior partner and the strongest internal brake on defense liberalization, ended its 26-year coalition with the LDP in October 2025. Prime Minister Takaichi Sanae, who won a general election in February with backing from the Nippon Ishin no Kai, is more openly hawkish on Taiwan than her predecessors. 

After her parliamentary remarks in November 2025 about a possible Taiwan contingency, China imposed a series of economic measures on Japan. On January 6, Beijing tightened dual-use export controls toward Japanese military end-users, followed on February 24 by the addition of 20 Japanese defense firms, including Mitsubishi Heavy Industries, Kawasaki, and IHI, to Beijing’s Export Control List. By any reasonable measure, China is already retaliating against Japan as if Tokyo were directly arming Taipei.

In August 2025, Canberra selected the upgraded Mogami as its preferred platform for the Royal Australian Navy’s general-purpose frigate program. In April 2026, Australia signed the formal contract with Mitsubishi Heavy Industries for the first three ships, with the remaining eight to be built in Western Australia under technology-transfer arrangements. The first three frigates are valued at about A$10 billion, with the broader program expected to reach roughly A$20 billion over the decade. The ships displace about 3,900 tons, operate with a crew of around 90, and combine anti-submarine, anti-surface, and air-defense capabilities, making the Mogami class a multi-role design intended for sustained operations across the Indo-Pacific.

What makes the agreement consequential is the architecture around the platform. Tokyo set up a dedicated joint committee to coordinate the bid, agreed to substantial intellectual property transfer, and embedded the program in a wider Australia-Japan security relationship anchored by the Reciprocal Access Agreement. The result, rather than a one-off sale, is a multi-decade industrial partnership. The significance of these arrangements extends beyond shipbuilding itself; Japan’s industrial capacity is  a........

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