First Operational Use of the Type 25 Missile in Japan-U.S. Joint Exercises in 2026 to Realize Southwest Defense

The Japan Ground Self-Defense Force is expected to deploy the Type 25 anti-ship guided missile, stationed at the Kengun Garrison in Kumamoto Prefecture, for the large-scale Japan-U.S. joint exercise "Keen Sword" starting in October. According to the Mainichi Shimbun (Kyodo News) on September 26, sources from the Ministry of Defense indicated that the missile will be moved from Kengun to the Oyanohara Training Area in the same prefecture, where it will share target information and launch procedures with the U.S. military. It is reported that live-fire exercises will not be conducted.

New Role of the Type 25

The photo shows a training exercise for the related Type 12 anti-ship guided missile. This is not an actual image of the Type 25.

The Type 25 is a core component of Japan's stand-off defense capability, significantly extending the range of the conventional Type 12 anti-ship guided missile. As indicated in the Ministry of Defense's "Defense of Japan 2026," Japan is developing the ability to strike maritime targets from outside the range of Chinese naval and air activities and North Korea's missile capabilities. The key aspect of this exercise is not the launch itself, but the connection between Japan and the U.S. in receiving the same target information and linking detection, judgment, and engagement procedures.

Sharing "Intent" More Challenging than Capability

Incorporating the Type 25 into joint exercises with the U.S. military is an attempt to connect the dispersed Japan Ground Self-Defense Force units in the southwestern islands with U.S. naval and air force sensors. When Chinese vessels pass through the Miyako Strait or the East China Sea, deterrence cannot be established solely by missile range. Identification of targets, rules of engagement, consideration for civilian shipping routes, and political approval for launches must progress at the same pace.

Moreover, the fact that the units will move from Kengun to the training area provides an opportunity to verify the mobility and secrecy of the forces. Fixed launch sites are easily detected by satellites and drones. Conversely, if the effectiveness of movement, including roads, fuel, and communications, is lacking, the numbers related to long-range capabilities will not be effective on the battlefield.

Implications for the Japan-U.S. Alliance

When viewed alongside the Ministry of Defense's official announcement regarding the expansion of cooperation with the U.S. and South Korea, the participation of the Type 25 in training indicates that Japan is not simply shifting away from "defensive-only" policies, but has entered a phase of incorporating retaliatory capabilities into joint plans with its allies. However, in this training, which does not involve live ammunition, the accuracy of targeting under communication disruption and resupply after repositioning cannot be confirmed.

The true test is not the missile's flight performance, but whether Japan and the U.S. can share the same situational picture during a crisis within minutes.

If the number of equipment is increased while leaving this point ambiguous, it may not strengthen deterrence but rather institutionalize delays in judgment.

References

• Mainichi Shimbun (Kyodo News) "Japan-U.S. drill to start October to involve Japan's long-range missiles" September 26, 2026
• Ministry of Defense "Defense of Japan 2026"
• Ministry of Defense / Self-Defense Forces "Japan-Mongolia Defense Ministerial Meeting" September 30, 2026