Japan's Ministry of Defense Requests FY2027 Budget of 8.9 Trillion Yen to Accelerate Unmanned Operations and Change the Burden-Sharing in the Japan-U.S. Alliance

On August 31, the Japanese government submitted its budget request for the fiscal year 2027 defense budget. The requested amount is approximately 8.9 trillion yen. More noteworthy than the figure itself is the shift in focus of the document from the traditional "fundamental strengthening of defense capabilities" to "transformation of defense capabilities" in line with changing methods of warfare.

The Axis of Equipment Procurement Shifts from Manned Aircraft to Composite Systems

According to the Ministry of Defense's materials, there is a clear direction towards combining AI, low-cost, high-lethality unmanned aerial systems (UAS), and electronic warfare (EW). Multiple unmanned systems for both attack and interception, low-cost stand-off missiles, as well as existing long-range weapons like hypersonic guided missiles and AGM-158 JASSM are included. This approach is based on the idea of not relying on a single expensive platform but rather preparing a quantity with the assumption of attrition.

For the Japan Maritime Self-Defense Force, the consideration of expanding the operation of unmanned underwater vehicles (UUV) is also significant. There are many missions that UUVs can undertake, including anti-submarine warfare, mine countermeasures, and port surveillance. However, if detection data cannot be integrated quickly into naval vessels, aircraft, and U.S. military command systems, increasing the number of platforms will not directly enhance the protection capability of sea lines of communication (SLOC).

Practical Changes in the Japan-U.S. Alliance

In terms of role-sharing with the United States, Japan is showing a stance that goes beyond merely providing bases and supporting manned assets, by enhancing the sensor density and missile defense along the first island chain. Unmanned systems and UUVs are politically easier to manage and suitable for continuous monitoring in dangerous maritime areas. On the other hand, weaknesses include autonomy under communication jamming, a shortage of maintenance personnel, and stockpiles of ammunition and spare parts.

Forecast International analyzes this request as an adaptation to the "new ways of warfare" demonstrated in Ukraine and the Middle East, as well as an expansion of the production capacity of the defense industry. The defense white paper also points out the collaboration and technological changes among China, Russia, and North Korea, and a policy has been indicated to revise three documents, including the national security strategy, by the end of the year.

Constraints That Cannot Be Overlooked

The requested amount does not directly translate into combat capability. Amidst a weak yen and personnel shortages, even if research and development costs are accounted for, if mass production, training, and data sharing do not progress, the deterrent effect will be limited. Particularly for UUVs, the updating of nautical charts and acoustic information, as well as the joint operational procedures between Japan and the U.S., will be critical to success.

The real challenge is not whether we can buy unmanned equipment, but whether we can operate it as a system that can be replenished if lost, on the same operational map as manned units.

This budget request is an attempt for Japan to transition from being a rear base for the U.S. to an active partner in the alliance responsible for maritime surveillance and air defense and strike capabilities. However, the most precarious issue is not the lack of equipment, but the inability of decision-making and industrial speed to keep up with procurement speed.

Sources

• Japan Ministry of Defense FY2027 Budget Request Overview (August 31, 2026)
• Forecast International, Japan Confronts the New Ways of War in FY2027 Budget (September 9, 2026)
• The Yomiuri Shimbun, Defense & Security