Japan's defense industry is accelerating its push into the global arms market after the country abolished its 60-year-old ban on "lethal weapons exports." Under the postwar pacifist constitution, Japan had only allowed exports of weapons for five purposes: rescue, transport, alert, surveillance, and minesweeping. However, when Prime Minister Sanae Takaichi scrapped the "Three Principles on Transfer of Defense Equipment" on April 21, the shackles on arms exports were removed.
While citing the deteriorating security environment in the Indo-Pacific region as justification, Japan's underlying intention appears to be cultivating its munitions industry as a national strategic sector. Japan's moves are gathering pace. Just two weeks after the lifting of the arms export ban, Defense Minister Shinjiro Koizumi visited Indonesia and the Philippines in succession from the 3rd to the 7th of this month, in what is seen as an active push for defense sales.
Japan is exploring the export of Oyashio-class submarines to Indonesia. Reports indicate it is also pushing to transfer soon-to-be-retired Abukuma-class destroyer escort frigates to the Philippines. Support at the Japanese government level has also begun. Prime Minister Takaichi has personally stepped in. On the 8th, she visited Vietnam to meet with Prime Minister Le Minh Hung and discuss defense and security cooperation, lending her weight to the effort.
According to local Philippine media, Defense Minister Shinjiro Koizumi held talks in Manila with Philippine Defense Secretary Gilberto Teodoro and agreed to establish a working-level consultation framework for the export of used frigates. If Japan's used frigate export materializes, it will be the first export case since the Japanese government permitted lethal weapons exports.
Japan is likely to expand exports centered on the maritime and air defense sectors. These are areas where Japanese manufacturing has strengths, including advanced radar systems, patrol vessels, and interceptor missiles. They are also the hottest segments in the global defense market. With demand rising amid complex conflicts including the Iran war, competition among U.S. allies to secure key weapons such as air defense missiles, artillery shells, and warships has intensified.
Furthermore, Japanese defense firms such as Mitsubishi Heavy Industries, Kawasaki Heavy Industries, and IHI are evaluated as having world-class technology. This is why tensions are running high in K-Defense. "The vessels, aircraft, and submarines Japan seeks to export significantly overlap with areas where Korea has strengths," a defense industry official said. "In the long term, competition is inevitable."
As Japan focuses on ASEAN and maritime defense, competition with K-Defense has begun. Indonesia and the Philippines are key partners for K-Defense, but as Japan's arms export gates open, concerns are emerging that these countries are expanding the scope of their dealings toward Japan. Going further, observers suggest Japan and K-Defense are bound to clash in the aviation sector, a next-generation growth area.
In 2022, Japan partnered with the United Kingdom and Italy to develop a sixth-generation stealth fighter, the Global Combat Air Programme (GCAP), targeting deployment in 2035. While Korea's 4.5-generation KF-21 Boramae fighter, which has just entered mass production, is not an immediate competitor, Japan plans to leverage its sixth-generation fighter platform to target the Australian, Indian, and ASEAN markets, making future competition impossible to rule out.
Of course, K-Defense currently holds the upper hand in the short term. According to the Stockholm International Peace Research Institute (SIPRI), which compiles defense market export shares every five years, Korea ranked 9th globally (3.0%) for 2021-2025. Japan, meanwhile, was not included in the list, which goes down to 30th place. This is because Japanese defense, having long been domestic-focused, lacks experience in international defense marketing and large-scale exports.
However, Japan's underlying strengths, including its technological capabilities, cannot be ignored. On April 18, Australia signed a $7 billion (approximately 10.5 trillion won) contract with Mitsubishi Heavy Industries to purchase next-generation Mogami-class frigates. This was a project in which Korea's Hanwha Ocean (042660.KS) and HD Hyundai Heavy Industries had participated and lost. More recently, New Zealand is also exploring the purchase of Japan's Mogami-class frigates.
Some analysts say the Japanese government's lifting of the lethal weapons export shackles has given Japan's defense industry the optimal timing. This is being proven by performance. According to a May 13 report by Japan's Nihon Keizai Shimbun, buoyed by defense buildup policies, the combined defense business order backlog of Japan's three major heavy industry companies — Mitsubishi Heavy Industries, Kawasaki Heavy Industries, and IHI — totaled 6.25 trillion yen (approximately 59.01 trillion won) in their fiscal 2025 consolidated earnings, up 15% year-on-year.
"Japan has substantial technological capabilities in the maritime and aviation sectors, and is even pursuing joint development of next-generation fighters with Europe, so it can become a sufficiently threatening competitor in the medium to long term," said Eom Hyo-sik, head of the defense and security office at the Korea Defense and Security Forum. "A strong competitor has emerged in the maritime sector, and Japan is highly likely to become the biggest competitor in the ground and air sectors going forward as well."
