From "Defensive Defense" to "Proactive Deterrence" — The Acceleration of Japan's Security System Transformation Under the Takai Administration and Its Regional Ripple Effects

At the end of April 2026, the first meeting of the "Advisory Council on Security from the Perspective of Comprehensive National Power," held at the Prime Minister's Official Residence in Nagatacho, Tokyo, may be recorded in history as a fundamental turning point in Japan's security policy over the 80 years since World War II. Prime Minister Sanae Takaichi declared at the meeting that "the relatively stable international order after the Cold War has become a thing of the past," clearly indicating a commitment to fundamentally strengthen Japan's defense capabilities. Against the backdrop of the invasion of Ukraine, dramatic changes in the Middle East, and rising military tensions in East Asia, Japan is moving away from its traditional framework of "defensive defense" and steering towards the construction of proactive deterrence capabilities.

A symbolic event of this policy shift is the initial deployment of the Type 25 anti-ship guided missile announced by the Ministry of Defense on March 31, 2026. This new missile, deployed at the Kengun Garrison in Kumamoto Prefecture, boasts a range of approximately 1,000 kilometers, a significant extension from the previous Type 12 anti-ship guided missile's range of about 200 kilometers, and forms the core of Japan's "stand-off defense capability." The missile employs a low-observability design and features a target change capability during flight through update commands via satellite communication, providing dynamic engagement capabilities against moving maritime targets. This deployment is positioned as the first concrete realization of the "counterstrike capability" specified in the security documents revised in 2022.

The deployment of the Type 25 anti-ship guided missile is not merely an equipment update but plays a part in the structural transformation of Japan's entire defense doctrine. The Acquisition, Technology & Logistics Agency is currently developing ship-launched and air-launched variants of the Type 25 for deployment in fiscal year 2028, with the ship-launched version planned to be integrated into the Japan Maritime Self-Defense Force's destroyer Tsurugi and the air-launched version into the upgraded F-2 fighter. Furthermore, a new type of precision-guided missile for land-to-sea and land-to-land attacks, which began development in 2025, will have the capability to strike not only maritime targets but also critical land targets such as airfields, ports, and command and control facilities, aiming for operational deployment by fiscal year 2032. The development of hypersonic guided missiles is also progressing in parallel, advancing the construction of multi-layered long-range strike capabilities.

Driving these capability enhancements is the re-revision of the security documents promoted by the Takaichi administration. The advisory council includes 15 members, such as former U.S. Ambassador Yuichiro Sasayama, former Deputy Minister of Defense Tetsuro Kuroe, Professor Kazuto Suzuki from the University of Tokyo, and Professor Noriko Endo from Waseda University, aiming for a revision within the year. The focus of the revision is on adapting to new forms of warfare, such as the mass deployment of drones and battlefield applications of AI technology, as well as establishing continuous combat capabilities. The latter implies strengthening the domestic defense industrial base to enable autonomous procurement of munitions and weapons.

On April 21, 2026, the Japanese government abolished the three principles on the transfer of defense equipment. The regulations that limited the export of lethal weapons to five categories were removed, effectively lifting the ban on the export of lethal weapons. Prime Minister Takaichi stated, "There is no time to lose," expressing her determination to strengthen defense capabilities. This measure aims to enhance the competitiveness of the defense industry and improve combat readiness in emergencies, signifying a decisive departure from the post-war principle of prohibiting arms exports.

Alongside these shifts, the institutional transformation of the Self-Defense Forces is also progressing. In April 2026, the government solidified its policy to revise the rank titles of the Self-Defense Forces, with plans to submit a bill to the National Diet within the year. This will be the first revision since its establishment in 1954. The revision includes the revival of terms from the former Imperial Japanese Army, such as changing "Colonel" to "Colonel" and "Lieutenant General" to "General." The government cites consistency with international standards and fostering pride among personnel as reasons for the change. However, Ryo Sugita, a senior researcher at Ritsumeikan University, points out that the Ground Self-Defense Force has intentionally maintained a distance from the former Imperial Japanese Army, while military writer Kazutaka Kimura has condemned the revision proposal as foolish.

China's reaction has been extremely severe. The Global Times positioned the title of Colonel as a symbol of Japanese militarism and criticized the current government's actions as dangerous political ambitions. A researcher at the China Institute of International Studies pointed out that the current Japanese government lacks reflection on the history of militarism. South Korea's Chosun Ilbo also reported this as a step towards the regularization of the Self-Defense Forces.

On the other hand, Japan's strengthening of defense capabilities is also contextualized within the Japan-U.S. alliance. During the Balikatan 2026 exercise conducted in the Philippines from April 26 to 29, 2026, a multinational air defense network was demonstrated, centered around the U.S. Marine Corps' 3rd Coastal Regiment, integrating systems such as MADIS, AN/TPS-80 radar, the Army's Avenger and VAMPIRE systems, along with Japan's Type 11 short-range surface-to-air guided missile. The Philippine Air Force's SPYDER system and the Navy's frigates also participated, indicating that the Self-Defense Forces' equipment is being incorporated into practical operations with allied nations.

The ongoing security transformations in Japan are not merely a series of individual policy changes but a systematic shift interconnected with one another. The operational deployment of long-range missiles provides the physical foundation for counterstrike capabilities, the re-revision of the security documents grants strategic legitimacy to these capabilities, the abolition of the principles on the transfer of defense equipment ensures the sustainability of the defense industry, and the revision of rank titles transforms the institutional identity of the Self-Defense Forces. Participation in multinational exercises with allies indicates the pathway for these capabilities to be integrated into the regional security architecture. The transition from defensive defense to proactive deterrence is no longer a declaration but an ongoing reality, and whether this reality strengthens regional stability or triggers a new arms race depends on how transparently the Japanese government explains this transition and maintains strategic dialogue with neighboring countries.