The Deployment of Japan's First Domestic Long-Range Missiles Marks a Turning Point in East Asian Security.

On March 31, 2026, Japan will deploy its domestically developed long-range missile system for the first time in actual combat. This decision, announced by the Ministry of Defense on March 9, symbolizes a historic shift from Japan's post-war principle of "defensive defense" to the possession of "counterattack capability."

The system to be deployed is an improved version of the Type 12 surface-to-ship guided missile operated by the Japan Ground Self-Defense Force. This system, stationed at the Kengun Garrison in Kumamoto City, Kumamoto Prefecture, has significantly extended its range from approximately 200 kilometers to about 1,000 kilometers. As a result, areas along the Chinese coast and parts of the Korean Peninsula will fall within range from the garrison located in central Kyushu. The Ministry of Defense also aims to extend the range to 1,500 kilometers in the future, which would allow it to reach areas around Beijing.

The improved Type 12 surface-to-ship guided missile was approved for development by the Cabinet in December 2020, with a budget allocation of 33.5 billion yen in the fiscal year 2021. Development is set to be completed by December 2025, and the deployment, initially scheduled for fiscal year 2026, will be advanced. The missile's overall length has been extended, and its shape has been modified. It is equipped with the latest command and control links, and the durability of the engine has been improved to support long-term operations. As a core component of stand-off defense capability, it can attack targets from outside the enemy's attack range.

This deployment is based on three documents approved by the Cabinet in December 2022: the National Security Strategy, the National Defense Strategy, and the Defense Force Development Plan. These documents emphasize the need to respond to the "most severe and complex security environment since the post-war period," including China's maritime expansion, tensions in the Taiwan Strait, Russia's invasion of Ukraine, and North Korea's continued ballistic missile launches. Rear Admiral Akihiro Sato of the Japan Maritime Self-Defense Force also stated in his New Year remarks for 2026 that "it is essential to address these complex security challenges."

The development of counterattack capabilities is not limited to domestically produced missiles. The Japan Maritime Self-Defense Force's Aegis destroyer "Chokai" (DDG-176) will be equipped with Tomahawk cruise missiles within 2026, becoming the first ship to possess stand-off defense capabilities at sea. Japan has signed a procurement contract with the United States for 400 Tomahawks—200 Block IV and 200 Block V, along with 14 Tactical Tomahawk Weapon Control Systems—with the first delivery expected from late 2025 to early 2026.

However, there are concerns regarding the process of acquiring this historic capability. The most notable is the decision by the United States to redeploy some of the Patriot missile defense systems and THAAD (Terminal High Altitude Area Defense) missile systems stationed in Japan and South Korea to the Middle East in response to the worsening situation there. On March 10, both the Japanese and South Korean governments expressed concern over this move. The temporary reduction in air defense capabilities in East Asia is a significant issue for allies, especially considering North Korea's ongoing missile launches and increased military activities by China.

Interestingly, North Korea issued a warning on March 20, 2025, regarding Japan's plans to deploy long-range missiles in the Kyushu region. The Korean Central News Agency (KCNA) claimed that such attack capabilities would "lead to an escalation of constant tensions in Northeast Asia." The actual deployment proceeding as announced could provoke a backlash from North Korea.

On the other hand, efforts to strengthen multilateral cooperation in the region are also underway. On January 30, 2026, the defense ministers of Japan and South Korea agreed to elevate defense cooperation and announced plans to work on the joint development of artificial intelligence and unmanned weapon systems. Additionally, from February 20 to 26, 2026, the armed forces of Japan, the Philippines, and the United States conducted multilateral maritime cooperation activities (MMCA) within the Philippine exclusive economic zone. Amid shared concerns over China's activities in the South China Sea, such cooperative frameworks are gaining importance.

Tensions in the Taiwan Strait remain high. Chinese think tanks have identified the tension in the Taiwan Strait as the top geopolitical risk for Beijing in 2026, citing uncertainties surrounding the U.S. midterm elections and Japan's expanding involvement as concerns. The International Crisis Group (ICG) has also warned that the status quo in the Taiwan Strait is becoming increasingly unstable. On March 11, a U.S. Navy P-8A patrol aircraft passed through the Taiwan Strait, demonstrating a "commitment to a free and open Indo-Pacific."

Japan's recent decision is not merely an equipment update but a fundamental shift in security policy. It marks a transition from the "defensive defense" framework maintained for over 70 years post-war to a new stage where Japan possesses the capability to attack potential enemy bases. This is a realistic response to the changing nature of threats Japan faces and a significant step that will impact the regional power balance.

Kumamoto Prefecture Governor Takashi Kimura stated on March 9, "The prefecture has not received any notification. It is extremely regrettable to learn about it through the media," criticizing the lack of explanation to the local community. The Kyushu Defense Bureau later announced plans to hold an equipment exhibition at the garrison next week, inviting local representatives ahead of the March 31 deployment, but this lack of transparency remains a challenge for the future.

Japan's possession of counterattack capabilities is being pursued in coordination with its ally, the United States, but it also means that Japan itself will bear greater defense responsibilities. By simultaneously advancing the procurement of Tomahawks and the development of domestically produced missiles, Japan aims to establish a multi-layered deterrent system. However, merely acquiring capabilities is not enough. Clarifying operational doctrine, establishing command and control systems, and, above all, fostering public understanding are essential.

The deployment on March 31 is likely to become a turning point in the security environment of East Asia. How Japan will build effective deterrence while maintaining its image as a "peaceful nation" will be demonstrated by its actions over the next few years.