Japan commenced its joint military exercise with the United States on October 20, marking one of the largest bilateral drills to date amid escalating tensions with China. The Keen Sword exercise, scheduled to continue until October 29 across multiple locations in Japan, involves approximately 45,000 personnel from the Japanese Self-Defense Forces and around 12,000 U.S. troops.

A notable aspect of this year’s training includes the deployment of Japan’s Type 25 long-range surface-to-ship guided missiles outside their usual base in Kumamoto prefecture, located on the southern island of Kyushu. This marks the first time these missiles, which have a range of roughly 1,000 kilometers and are capable of reaching waters near Taiwan, are operated beyond their garrison since their initial arrival earlier in the year.

According to a Joint Staff spokesman from Japan’s Self-Defense Forces, the exercise will focus on verifying launch procedures for naval targets, although no live-fire exercises are planned. Complementing these efforts, the U.S. Marine Corps will deploy the NMESIS unmanned surface-to-ship missile system and the Madis integrated air defense system in Okinawa.

Hiroaki Uchikura, head of Japan’s Joint Staff, emphasized the strategic importance of the southwestern region’s geographical and operational characteristics in shaping the scale of the exercise. He stated that the ability to rapidly and flexibly deploy forces in this area is essential. Uchikura described the current iteration of Keen Sword as reaching near-maximum scale, reflecting heightened concerns over regional security and a strong demand for rigorous training.

Relations between Tokyo and Beijing have deteriorated significantly over the past year, particularly after Prime Minister Sanae Takaichi suggested last November that Japan could intervene militarily should Taiwan face an armed attack. This development has contributed to a more urgent and extensive military collaboration between Japan and the United States.