June 25, 2025
Japan, the United States, and Australia conducted a joint command-post exercise from late August to mid-September of last year, but the Ministry of Defense classified this exercise as a “specified secret”, and had kept it hidden from the public.
Akahata learned of this fact on June 24 from documents it obtained through an information disclosure request.
The exercise in question is called “Yama Sakura (YS)86”. It was a joint command-post exercise between the Ground Self-Defense Force (GSDF) and the U.S. and Australian armies.
The Ministry of Defense only disclosed the cover page of the documents. The cover page is marked “Specified Secret” with a diagonal line on it, indicating that the classification has been lifted.
In response to an Akahata inquiry, the ministry explained that YS86 was a “face-to-face coordination meeting to prepare plans for Yama Sakura 87”.
However, an article on the U.S. Indo-Pacific Command website specifies “YS86” as a “military exercise”. The article emphasizes, “This exercise serves as a vital platform for refining joint operations and improving strategic responsiveness across the Pacific theater.” It says, “In the vast expanse of the Indo-Pacific theater, Yama Sakura 86 emerges not just as a military exercise but as a pivotal testament to evolving alliances and strategic foresight.” It also features a commander’s comment saying, “These scenarios test our capabilities and push our forces to integrate seamlessly, preparing us for real-world challenges.”
Evidently, YS86 was an exercise based on a scenario that simulated actual combat.
Akahata learned of this fact on June 24 from documents it obtained through an information disclosure request.
The exercise in question is called “Yama Sakura (YS)86”. It was a joint command-post exercise between the Ground Self-Defense Force (GSDF) and the U.S. and Australian armies.
The Ministry of Defense only disclosed the cover page of the documents. The cover page is marked “Specified Secret” with a diagonal line on it, indicating that the classification has been lifted.
In response to an Akahata inquiry, the ministry explained that YS86 was a “face-to-face coordination meeting to prepare plans for Yama Sakura 87”.
However, an article on the U.S. Indo-Pacific Command website specifies “YS86” as a “military exercise”. The article emphasizes, “This exercise serves as a vital platform for refining joint operations and improving strategic responsiveness across the Pacific theater.” It says, “In the vast expanse of the Indo-Pacific theater, Yama Sakura 86 emerges not just as a military exercise but as a pivotal testament to evolving alliances and strategic foresight.” It also features a commander’s comment saying, “These scenarios test our capabilities and push our forces to integrate seamlessly, preparing us for real-world challenges.”
Evidently, YS86 was an exercise based on a scenario that simulated actual combat.
