Japan has introduced a bold one-theater strategy to the United States, aiming to enhance regional defense cooperation. Defense Minister Gen Nakatani presented the proposal to U.S. Defense Secretary Pete Hegseth during a meeting in Tokyo on March 30.
This one-theater strategy treats the East China Sea, South China Sea, Korean Peninsula, and surrounding zones as a unified defense area. Traditionally, these regions were considered separate in terms of military operations.
According to government officials, Nakatani urged greater cooperation between Japan, the U.S., South Korea, Australia, and the Philippines. He emphasized the need to treat these countries as partners within the one-theater strategy.
Hegseth reportedly welcomed Japan’s proposal. Later that day, he also discussed the strategy with Prime Minister Shigeru Ishiba. He highlighted the growing need for regional unity in response to potential threats from China.
Japanese defense officials created the one-theater strategy to better align with the Indo-Pacific security focus. This approach comes as Japan looks to play a stronger regional role under the Trump administration in the U.S.
The new strategy intends to prepare Japan and its allies for emergencies in this combined region. It reflects growing concerns over China’s expanding influence in both the East and South China Seas.
However, the exact boundaries of the one-theater strategy remain undefined. This lack of clarity has raised concerns within Japan’s Defense Ministry. Critics worry that unclear limits could draw the Self-Defense Forces into unforeseen foreign conflicts.
One official stressed that the term “theater” should not be used with other countries until details are finalized. Another senior official added that ministry consensus is still lacking on the precise definition of the one-theater strategy.
Despite these concerns, the proposal marks a significant shift in Japan’s regional defense posture. The one-theater strategy may become a foundation for deeper Indo-Pacific military cooperation.
