On August 5, 2025, Australian Deputy Prime Minister and Minister for Defence Richard Marles made a historic announcement: the adoption of upgraded Mogami-class frigates produced by Japan’s Mitsubishi Heavy Industries (MHI) for the Royal Australian Navy (RAN)’s SEA3000 General-Purpose Frigate (GPF) program. Under the program, after importing the first three vessels in a fully built state, Australia is set to construct the remaining eight vessels at the Henderson shipyard in Western Australia. The first completed frigate will be handed over to Australia in 2029, and is scheduled to enter service in 2030.
For Japan, this marks the biggest order for large-scale defense equipment since the export of an air surveillance radar system to the Philippines in 2023. If the plan to construct the frigates in Australia goes forward, it would also be the first time Japanese-designed defense equipment is manufactured overseas. Not only is this a significant achievement for the Japanese defense exports reforms, which have been underway since the 2010s, it stands as a landmark event in the history of Japan’s security policy.
It also represents Japan overcoming the heartbreak of 2016, when its bid to supply the vessels for Australia’s next-generation submarine program ended in failure. As this time, in 2016 the equipment Japan proposed was arguably superior to that of its rivals in terms of both performance and technology, yet Japan failed to secure an order. And like its previous attempt, Japan’s defense industry today is still at a similar disadvantage due to its inexperience with overseas manufacturing. That raises the question of what was different about this time compared with 2016.
First of all, it was about exporting defense equipment tailored to the needs of the RAN. The Soryu-class submarine that Japan tried to export from 2015 to 2016 boasted excellent capabilities and reliability, but it was designed to operate in the waters around the Japanese archipelago, and was not particularly well suited to operating in the Southern Hemisphere and across the vast maritime areas required by the RAN.
Meanwhile the upgraded Mogami-class frigates have been described as the best match for RAN’s operational requirements in terms of both range and firepower. Inoue Rintaro of the Asia Pacific Initiative (API) pointed out that the performance of Japan’s new FFM (multi-mission frigate) design, which boasts a range of 10,000 nautical miles, is a big draw for a next-gen frigate.
The second factor was the level of commitment on the Japanese side. Former Prime Minister Abe Shinzo and his administration were the main driving forces behind the pitch to sell Soryu-class submarines, but neither the Ministry of Defense nor the Japanese private sector shared Abe’s enthusiasm. The Japan Maritime Self-Defense Force (JMSDF) in particular was opposed to sensitive information related to its prized Soryu-class submarine falling into the hands of a third country via Australia. At the same time MHI, which does business in China, was reluctant to go into business with Australia given the strategic implications for its Asian neighbor. It is also understood that Japan presented a downgraded version of its Soryu-class during the final selection process, which would have become a cause for disappointment on the Australian side.
This time was different. Japan viewed the push to sell general-purpose frigates to Australia as part of its broader defense industry export strategy, and this turned into an “all-Japan” effort uniting the public and private sectors. In December 2024, a Joint Public-Private Promotion Committee for the Sale of General-purpose Frigates was established, with members including Japan’s Ministry of Foreign Affairs and Ministry of Economy, Trade and Industry in addition to the Ministry of Defense and companies from the private sector. MHI also showed it was serious about a deal by setting up a temporary office in Canberra.
In January 2025, General Yoshida Yoshihide, former chief of staff, Joint Staff of the Japan Self-Defense Forces (JSDF), expressed a willingness to prioritize joint development and production with Australia even if it meant postponing the JMSDF’s own program. This gesture likely resonated with the Australian side, given that its current lack of surface combat capabilities meant it sought speed and certainty of delivery above all else.
The deciding factor came down to the level of trust between the two countries. Already by 2016, security cooperation between Japan and Australia had advanced to a considerable degree, in part thanks to bilateral relations being elevated to a “Special Strategic Partnership” in 2014. Even so, Japan and Australia had not established mutual understanding or a relationship of trust in the truest sense. As is already evident, despite Australia being far ahead of Japan in terms of security clearances, Japan was paranoid about sensitive information leaking to third countries via Australia. For its part, Australia was unsure just how enthusiastic Japan was about selling its equipment, and also harbored doubts about its local shipbuilding capacity. This lack of mutual understanding and trust was the fundamental reason behind the breakdown in cooperation over the submarines.
In the years since then, both countries have continued along the path of cooperation aimed at strengthening ties, including defense sector ties. In June 2023, Japan and Australia signed a bilateral Research, Development, Test, and Evaluation (RDT&E) arrangement. Some months later, in January 2024, the two countries inaugurated the Joint Research Project on “Robotic and Autonomous Systems for Undersea Warfare” (RASUW). Then, right before this latest announcement, it was announced that Japan would officially take part in an Australia, U.K., and U.S. (AUKUS) program to test autonomous underwater acoustic communications systems. Each of these developments took cooperation between the two countries’ defense industries to new levels of mutual understanding and fostered greater trust.
The announcement that Australia will acquire Mogami-class frigates from Japan will surely strengthen bilateral cooperation still further, both in the strategic realm and between their respective defense industries. An added bonus is that if working with Japan helps boost Australia’s shipbuilding industry, it could also align with the strategic vision of strengthening AUKUS while advancing defense industry cooperation in the Indo-Pacific region. As such, this latest development could carry immense significance, not only for Australia-Japan relations but for security throughout the Indo-Pacific Region.