Japan's Type 25 Anti-Ship Guided Missile Participates for the First Time in 2026 Keen Sword, Operationalizing Southwest Defense

In the Japan-U.S. joint integrated exercise "Keen Sword," which began on October 19, the Japan Ground Self-Defense Force's Type 25 anti-ship guided missile was incorporated into an operational scenario for the first time. The core of this exercise lies in linking the vehicle-mounted missile, with a range of approximately 1,000 kilometers, to operational concepts in the southwest region, including Ishigaki Island, located about 270 kilometers from Taiwan.

Defense Concepts Demonstrated by the Type 25 Missile

According to Mainichi Shimbun (Kyodo News), the Type 25 practiced a series of procedures from target detection to launch, with four related vehicles moved from the Kumamoto Kengun Garrison to the Oyanohara Training Area in Kyushu. This is not merely a venue to showcase the performance of new equipment. It serves as a test to see if launchers, command communications, and target information can be distributed and connected to the same engagement plan with the sensor information from the Japan Maritime Self-Defense Force, Japan Air Self-Defense Force, and U.S. military.

Japan-U.S.-Australia Interoperability

Approximately 45,000 personnel from Japan, about 11,000 from the U.S., 40 ships, and 260 aircraft are participating. The Australian Department of Defence explained that around 300 personnel from Australia, including P-8A patrol aircraft, the Anzac-class frigate "Stuart," and cyber and space personnel, are also involved, conducting experiments on autonomous systems, underwater acoustic communication, and command and control. This is an attempt to strengthen the layers of information and communication not only for air defense and anti-ship operations but also to maintain sea lines of communication (SLOC).

Simultaneity with Chinese Navy Actions

Meanwhile, Defense News reported on October 14 that the Chinese Navy's aircraft carrier "Liaoning" headed towards the western Pacific and conducted takeoffs and landings of carrier-based aircraft about 250 kilometers south of Ishigaki Island. This clarifies the geographical realities anticipated by the exercise. While it is not necessary to immediately conclude that Liaoning's voyage is a sign of crisis, it cannot be denied that we have entered an era where peacetime training continuously pressures the opponent's vigilance, communication, and supply.

Overlooked Constraints

Australia, Canada, France, Germany, New Zealand, the Netherlands, and the Philippines also participated, advancing multilateral cooperation. However, as the number of participating countries increases, it becomes more challenging to standardize rules of engagement, the scope of target information disclosure, and authority delegation during communication disruptions. The speed of political approval for launches and the speed of delivering accurate information to dispersed units may become operational bottlenecks, more so than the range of the Type 25. The challenge for the Japan-U.S. alliance is not only the lack of equipment but also whether decision-making can be standardized in peacetime when increasing allied nations.

Reference Information

• Ministry of Defense/Mainichi Shimbun (Kyodo News) "Major Japan-U.S. joint military drills kick off to boost regional defense," October 20, 2026
• Australian Department of Defence, “Australia joins Japan and United States as Exercise Keen Sword commences,” October 20, 2026
• Defense News, “China’s first aircraft carrier forms ‘evolving pattern’ of voyages in disputed Asian seas,” October 23, 2026