Why Is the U.S. Sending NMESIS to Yonaguni Near Taiwan?

Japan’s Ground Self-Defence Force has taken its new Type 25 surface-to-ship missile out of its home base for the first time, moving launchers from Camp Kengun in Kumamoto to the Onobaru training area on Kyushu for the Keen Sword 27 exercise with the United States, which opened on October 19. The Japanese daily Yomiuri Shimbun reported on October 20 that crews will rehearse the procedures for locating and targeting enemy warships, with the Japan Joint Staff having confirmed that no missile will be fired. The exercise also sees the U.S. Marine Corps deploy its NMESIS anti-ship missile system to Yonaguni, Japan’s westernmost inhabited island about 110 kilometres from Taiwan, for the first time. The two deployments highlight how far Tokyo and Washington have gone in turning the southwestern islands of Japan into a belt of missile positions covering the waters around Taiwan.

Keen Sword 27 is the largest joint exercise the two allies have staged, with the Japan Joint Staff having announced on September 29 that about 45,000 Japanese personnel, 6,100 vehicles, 40 vessels and 260 aircraft would take part, and the Okinawan daily Ryukyu Shimpo reporting that around 12,000 U.S. personnel bring the total to some 57,000. According to a Japanese Defence Ministry planning document reported by Stars and Stripes, about 60 personnel from the 12th Marine Littoral Regiment and the U.S. Army will deploy to Yonaguni with NMESIS and the MADIS short-range air defence system, with both systems also returning to Ishigaki and joining HIMARS rocket artillery on Tanegashima. Opening the drills at Camp Ishigaki, the commander of Japan’s Joint Operations Command stated, according to the Joint Staff: “We do not want crisis, confrontation, or a unilateral change to the status quo by force.”

The Type 25 is the product of the upgraded Type 12 program, the centrepiece of the counterstrike capability adopted in Japan’s December 2022 National Security Strategy. Where the original Type 12 developed by Mitsubishi Heavy Industries has a range widely estimated at around 200 kilometres, the Type 25 is reported to reach roughly 1,000 kilometres, enough to cover most of the East China Sea from launch sites on Kyushu. The first launchers were stationed at Camp Kengun on March 31, with Tokyo having also signed in January 2024 for up to 400 American Tomahawk cruise missiles to bridge the gap. The exercise follows the Chinese carrier Liaoning sailing past Okinawa with two Type 055 class destroyers days before the drills began.

NMESIS mounts two Naval Strike Missiles on an unmanned Joint Light Tactical Vehicle, the same Kongsberg missile Denmark has ordered for its frigates, with a range of more than 185 kilometres by most published estimates. The system first deployed on Okinawa in July 2025 and operated from Ishigaki during the Resolute Dragon exercise that September, with the 12th Marine Littoral Regiment, formed in November 2023, built to hold maritime chokepoints from islands within range of Chinese weapons. On October 18 a Japan Air Self-Defence Force C-2 transport was seen unloading what the Ryukyu Shimpo reported to be a U.S. radar at Yonaguni Airport. Japanese forecasts show Typhoon No. 30 approaching the Sakishima Islands, which include Yonaguni and Ishigaki, as early as October 23, six days before the exercise is due to end.