The New Stage of Alliance Deepening Shown by Japan-U.S. Integrated Training FST-J 26-71: The Intersection of the Middle East Crisis and East Asian Security

From February 23 to 27, 2026, the U.S. Forces Japan Command at Yokosuka Base and command and control centers throughout the region conducted the Fleet Synthetic Training Joint (FST-J) 26-71 with Japan and the United States. This training serves as an important example of how the Japan-U.S. alliance is enhancing its practical integrated operational capabilities in a rapidly changing geopolitical environment. Notably, this training was conducted during a time of heightened concern over China's military technological advancements and when tensions in the Middle East began to affect the defense posture in East Asia.

The FST-J training takes the form of exercising complex operational scenarios using advanced simulation technology rather than deploying actual vessels and aircraft at sea. This allows for training that can assume a wider variety of high-difficulty situations without being constrained by weather or maritime conditions. In this 26-71 training, it is believed that the Japan Maritime Self-Defense Force and the U.S. Navy's Seventh Fleet played central roles, incorporating a wide range of operational elements such as command and control, information sharing, integrated firepower operations, and ballistic missile defense. Particularly in recent years, the normalization of North Korea's medium-range ballistic missile launches in the Sea of Japan has been noted, and in October 2022, five vessels from Japan, the U.S., and South Korea conducted a multilateral ballistic missile defense exercise in the Sea of Japan. It is considered that one of the main objectives of this FST-J training was to enhance capabilities to respond to such ballistic missile threats.

The emphasis on the integrated operational capabilities of the Japan-U.S. alliance is underpinned by a significant change in security awareness within Japan. According to a government survey conducted in January 2026, 68% of Japanese respondents cited "China's military technological advancements and activities around Japan and in the South China Sea" as their greatest security concern. This figure surpasses the long-standing top concern of North Korea's missile issues, indicating that the Japanese public is acutely aware of changes in the regional military balance. The People's Liberation Army Navy of China has steadily improved its long-range operational capabilities beyond the first island chain, making the security of sea lines of communication (SLOC) and the maintenance of maritime domain awareness (MDA) critically important for Japan.

In response to this situation, Japan is also actively working to strengthen frameworks for multilateral cooperation in the region. On February 28, 2026, a maritime and air exercise was conducted in the Bashi Channel, a strategic chokepoint located between Taiwan and the Philippines, with the participation of both Japan and the U.S., along with the Philippines. The Bashi Channel is an important waterway connecting the western Pacific and the South China Sea and serves as a major transit point for Chinese naval vessels entering the Pacific. The participation of the Japan Maritime Self-Defense Force in exercises in this area symbolically indicates that Japan's defense scope is expanding beyond the traditional concept of "defensive defense" to contribute to the stability of the entire region.

However, the strategic environment surrounding the Japan-U.S. alliance is not limited to East Asian issues. In early March 2026, reports emerged that the U.S. might transfer the THAAD missile defense system and Patriot air defense system deployed in South Korea to the Middle East. This is a response to the escalating tensions in the Middle East following attacks on Iran by the U.S.-Israel coalition, but concerns have also been raised about creating a security vacuum in East Asia. On March 5, the Japanese government revealed that it was preparing to have Self-Defense Force aircraft on standby in the Maldives for the evacuation of Japanese nationals in the Middle East. Additionally, the government indicated that if Iran were to block the Strait of Hormuz, it would "make judgments on a case-by-case basis" regarding whether Japan would exercise collective self-defense.

The issue of the Strait of Hormuz presents Japan with a particularly delicate decision. Approximately 90% of the crude oil that Japan imports comes from the Middle East, with the majority passing through the Strait of Hormuz. If the strait were to be blocked, Japan's energy security would suffer a severe blow. Since the revision of security legislation in 2014, Japan has been able to exercise collective self-defense in cases that qualify as "situations threatening Japan's survival," but the interpretation of the conditions for activation remains cautious. Currently, the government has expressed the view that "it does not yet qualify as a situation threatening Japan's survival," but if the situation worsens, responses including the dispatch of minesweeping vessels from the Maritime Self-Defense Force may be considered.

Thus, Japan's defense policy has entered a complex phase where it must simultaneously respond to crises in two different theaters: East Asia and the Middle East. Integrated training exercises like FST-J 26-71 are essential tools for enhancing responsiveness and flexibility in addressing these multifaceted security challenges. The interoperability, common tactical procedures, and rapid decision-making mechanisms built through training will directly contribute to strengthening deterrence in peacetime and effective joint operations in times of crisis.

Looking ahead, further deepening of integration within the Japan-U.S. alliance is anticipated. Cooperation in new domains such as space, cyber, and electromagnetic spectrum, joint development and operation of long-range precision strike capabilities, and strengthening of integrated air and missile defense (IAMD) systems are expected to be key areas of focus. Additionally, the possession of "counterstrike capabilities" (capabilities to attack enemy bases), which Japan decided to pursue in a cabinet meeting in 2022, is expected to be concretized in close coordination with the U.S. The FST-J training serves as an important opportunity to demonstrate the military unity of both countries and to send a deterrent message against potential threats in the region during this strategic transformation process.

Faced with the triple challenges of China's military rise, North Korea's nuclear and missile development, and geopolitical turmoil in the Middle East, Japan is accelerating its shift from a traditionally passive defense posture to a more proactive and integrated security strategy. FST-J 26-71 serves as an important indicator of the current state of the Japan-U.S. alliance at this turning point and is an exercise that should be closely monitored for future trends in regional security.