Japan and the United States launched their largest-ever joint military exercise on Monday, with roughly 56,000 personnel taking part in the 11-day Keen Sword 27 drills across Japan. The exercise, which runs until October 29, features Japan’s new Type-25 long-range anti-ship missile in simulated operations for the first time. Japan US military drills of this scale are held every two years and form the centerpiece of the alliance’s joint readiness training in the Asia-Pacific.
FAKTA: Keen Sword 27 in brief
- Exercise: Keen Sword 27, the 18th iteration of the biennial Japan-US field training exercise.
- Duration: October 19 to October 29, 2026, at Self-Defense Forces facilities and other locations across Japan.
- Forces: about 45,000 Japanese Self-Defense Forces personnel and around 11,000 US troops, plus contingents from seven partner nations.
- New systems: Japan’s Type-25 surface-to-ship guided missile (reported range of about 1,000 km) in simulated, non-live-fire use; US Marine Corps NMESIS anti-ship missile systems and MADIS air-defence equipment deployed to Yonaguni Island.
- Aircraft carrier USS Theodore Roosevelt joined the exercise after a port call at Yokosuka.
Japan US military drills put new missile on show
The exercise opened with a ceremony on Ishigaki Island in southwestern Japan, the country’s westernmost point, according to statements carried by Japanese and US outlets. Japan’s Joint Staff said Japanese forces are contributing about 45,000 personnel along with some 40 vessels and around 260 aircraft, while the United States is fielding approximately 11,000 troops.
The centrepiece of this year’s edition is the first operational appearance of Japan’s domestically developed Type-25 surface-to-ship guided missile. The missile, which has a reported range of about 1,000 kilometres, was moved from its home base at Camp Kengun in Kumamoto Prefecture to a training area covering parts of Nagasaki and Saga prefectures, where troops are rehearsing launch procedures without live firing. Japanese and US personnel are also expected to practise sharing targeting data.
On the American side, the Marine Corps is deploying its Navy-Marine Expeditionary Ship Interdiction System (NMESIS) and MADIS air-defence vehicles to Yonaguni Island, the Japanese island closest to Taiwan, for the first time. Japan is also temporarily placing Type-88 anti-ship missiles and Type-03 medium-range air-defence systems on Yonaguni, with Type-88 systems additionally stationed on Ishigaki Island.
Wide international participation
Keen Sword 27 brings together forces from Australia, Canada, France, Germany, the Netherlands, New Zealand and the Philippines, with South Korea and the United Kingdom sending observers. The training programme covers air and missile defence, maritime operations, logistics, casualty evacuation, facility protection and operations in space and cyberspace.
The exercise takes place amid strained relations between China and Japan over Taiwan, while both governments intend to keep the alliance’s largest field exercise on schedule. The US maintains long-standing military alliances across the region, with Japan and South Korea hosting tens of thousands of American troops and the Philippines granting US forces access to its bases. More on international developments is available on the Watan News English homepage.
