US mulls creating unified military command for Japan, looks to greater integration with SDF

WASHINGTON (Mainichi) -- The United States is considering putting all its forces in Japan under a new unified local headquarters within the U.S. Indo-Pacific Command, multiple sources here have told the Mainichi Shimbun.

The move comes after the Japanese government announced plans in December 2022 to create a joint command integrating operations of all branches of the Self-Defense Forces (SDF) -- ground, air, and maritime -- by fiscal 2027. In effect, the U.S. will be replicating the SDF's command integration for its own forces in Japan, aiming to smooth cooperation between U.S. and Japanese forces starting in peacetime. The policy also gives more focused direction to the Indo-Pacific Command's force realignment efforts, as it continues discussions with Tokyo on Japan's role.

At present, the functions of Headquarters U.S. Forces Japan, at Yokota Air Base in western Tokyo, are limited to administrative negotiations with the Japanese government and SDF, and coordinating implementation of the Status of Forces Agreement governing U.S. forces in the country. Operational control of U.S. forces here is held by the Indo-Pacific Command, based in Hawaii. The commander of U.S. Forces Japan is also the commander of the U.S. 5th Air Force, but observers have long pointed to insufficient coordination among the U.S. Army, Air Force, Navy and Marine Corps units.

According to U.S. government sources, in response to China's years-long military buildup, the Indo-Pacific Command has been reviewing its chain of command to prepare for any crisis. The Indo-Pacific Command is also said to be considering establishing a new joint headquarters covering all units in Japan in addition to strengthening the existing HQ at Yokota Air Base.

In the event of a contingency involving China, all of Japan could face missile attacks and other threats, leading some in the U.S. military to assert it would be better to keep command functions in Hawaii. However, belief has grown that U.S. Forces Japan should have a counterpart to the SDF's planned "joint command center" set out in Japan's National Defense Strategy, approved by the Cabinet this past December.

The U.S. military has regional commands covering the entire planet, each one composed of elements from all the armed services -- Army, Air Force, Navy and Marine Corps -- and commanded by a senior officer. The setup is designed to allow highly coordinated and effective combined arms operations. And the importance of the Indo-Pacific Command, which covers the entire Pacific Ocean east of India to just west of the U.S. mainland, is growing with the rise of China.

Advances in military technology have boosted the speed at which missiles and other weapons can be deployed, and more rapid decision-making is required in unit operations. This imperative is spurring calls within the U.S. military for greater operational integration between their forces and the SDF, which in turn form the background for the push for increased interoperability between the two forces.

Christopher B. Johnstone, Japan chair at the Washington-based Center for Strategic and International Studies think tank and a former director for East Asia on the U.S. National Security Council (NSC) under President Joe Biden, told the Mainichi that the permanent establishment of a joint SDF command is a significant step forward for Japan. He added that the U.S. must also consider what kind of command structure it needs in Japan to work closely with Tokyo.

As for integrating Japan-U.S. operations, Johnstone stated that it is not realistic to reach the level of unification seen between U.S. and South Korean forces. Rather, the U.S. and Japan will determine their respective integrated operational structure, and then consider what kind of combined operations is desirable.

(Japanese original by Shinichi Akiyama, Washington Bureau)