The Japanese F-X program, developed with the United Kingdom and Italy, aims to produce a sixth-generation fighter jet by 2035, symbolizing autonomy and innovation.
Summary
Japan’s F-X program (also part of the Global Combat Air Program – GCAP) aims to provide the Japan Air Self-Defense Force (JASDF) with a new sixth-generation combat aircraft. It is being carried out in cooperation with the United Kingdom and Italy, bringing together Mitsubishi Heavy Industries, BAE Systems, and Leonardo S.p.A. The schedule calls for a demonstrator around 2027 and entry into service around 2035. The program incorporates advanced technologies: stealth, electronic warfare, artificial intelligence, and loyal wingman drones. The budget amounts to tens of billions of euros. The F-X fighter will strengthen Japan’s strategic autonomy while shifting the geopolitical balance in the Asia-Pacific region.
The F-X fighter program and its strategic framework
The “F-X” fighter program was initially Japan’s national project to replace the Mitsubishi F-2, an aircraft developed with the United States and which entered service around 2000. In 2009, Japan launched studies to develop a new-generation aircraft with capabilities known as “i³ Fighter” (intelligent, integrated, instantaneous) in order to respond to growing regional air threats. In December 2022, Tokyo formalized the merger of its F-X project with the British-Italian Tempest program to form the GCAP, in which Japan plays a leading role. This tri-national framework combines technological innovation with cost optimization through industrial pooling. The choice of this alliance reflects the recognition that developing a sixth-generation aircraft alone was beyond the capabilities of a single country in terms of cost and technology. The program will take place against a backdrop of Chinese and Russian military build-up and a strategic realignment by the US in the Asia-Pacific region.
Expected innovations for a sixth-generation aircraft
The future F-X fighter falls into the “sixth generation” category, combining multiple advances. It is expected to feature increased stealth (reduced radar cross-section), internal weapon bays, advanced composite materials, and absorbent coatings. The planned engine—the IHI XF9—is designed to deliver more than 107 kN (10.9 tons) of thrust and aims for 147 kN (15 tons) with afterburner, according to the manufacturer. It is a “slim” engine to free up internal volume for fuel and weapons. The aircraft should also offer advanced integration of auxiliary drones, known as “loyal wingmen,” network management, high-intensity electronic warfare, artificial intelligence flight assistance, and possibly directed energy weapons. Emphasis is also placed on multi-platform connectivity and sensory data fusion. Pilots will need to cooperate with non-deployed units and autonomous systems. These features reinforce the JASDF’s air superiority and give it a strategic advantage in the Indo-Pacific arc.
Schedule, budget, and service entry objectives
The official schedule indicates a development launch in 2025, a demonstrator test flight planned for around 2027, and an estimated entry into operational service around 2035. However, Japanese sources have expressed doubts about this schedule and suggest a possible delay beyond 2040 if delays accumulate. The overall budget has not been fully disclosed, but it is estimated at tens of billions of euros (hundreds of billions of yen) for development, industrialization, and logistical support. Japan already amended its export rules in March 2024 to allow the sale of this aircraft abroad, opening up prospects for cost sharing through exports. The aim of relying on cooperation with the United Kingdom and Italy is precisely to spread the investment and reduce the risks associated with this type of ambitious project. Thus, the F-X/GCAP is as much a technological project as it is a financial one, providing structure for the Japanese defense industry.
Strategic alliances and industrial impact
The F-X program is not limited to simple aeronautical development: it has a strong industrial and diplomatic dimension. Japan, through Mitsubishi Heavy Industries, is collaborating with BAE Systems and Leonardo as part of the GCAP, through the international organization GIGO (Global Combat Air Program International Government Organization). This cooperation allows for the sharing of technologies, industrial workloads, and potential exports. Japan has also approached India to join the project in order to spread costs and develop a broader supply chain. However, a BAE official stated in July 2025 that adding a new partner could now delay the project. The industrial aspect aims to preserve Japan’s technological sovereignty and grow a national defense ecosystem capable of exporting. For the Japanese economy, it is a lever for creating highly skilled jobs, production, and research. This military-industrial alliance also projects Japan as a central player in international air defense beyond its traditional regional role.
The impact on the JASDF and Japan’s posture
For the Japan Air Self-Defense Force, the arrival of the F-X fighter will mark a qualitative leap. It will replace the F-2 from 2035 (or even 2040) onwards, and will be added to the fleet of F-35s already in deployment. The new aircraft will offer robust air superiority, increased interoperability with allies, and sufficient capability to respond to challenges posed by the Chinese and Russian militaries. It will enable the JASDF to maintain a credible deterrent capability in the Western Pacific arc, including the southern islands of Japan. The modernization of bases, infrastructure, and logistics is concurrent. In the event of a delay in the schedule, Japan will need to increase its transitional capabilities—such as the additional purchase of F-35s—to fill any potential capability gap. This fighter is part of a broader vision to amplify Japan’s defense capabilities, both quantitatively and qualitatively.
Geopolitical impact and regional challenges
The F-X / GCAP program is part of a tense geopolitical landscape. Japan is no longer seen as a mere customer for American weapons, but as a potential developer and exporter. This is changing the air power balance in the Asia-Pacific region, with Tokyo claiming greater strategic autonomy in the face of China’s rise and Russia’s projection of power. This triangular project with the United Kingdom and Italy also sends a strong diplomatic signal of a transatlantic technological alliance as an alternative to dependence on the US. Furthermore, the intention to export this aircraft to partners reinforces Japan’s role as an arms supplier on the world stage. Finally, in a context of maritime and air pressure around Taiwan, the Senkaku Islands, and the Japanese archipelago, this new fighter could tip the strategic balance of deterrence and military engagement.
Risks, challenges, and conditions for success
Despite its ambitions, the program faces concrete challenges. The tight schedule (2035) is considered optimistic and could slip beyond 2040. The high cost requires strict budgetary discipline and returns on investment through exports. On the technical side, innovations (AI, auxiliary drones, stealth, open architecture) must be validated without major damage. Japan must also manage multinational coordination between partners with different priorities. Finally, changes to export rules also create ethical and legal constraints within the Japanese constitutional framework. Success will depend on the ability to deliver a high-performance aircraft on time, control the industrial chain, and secure a sufficiently large export market.
The F-X fighter program represents a turning point for Japanese air defense and the national arms industry. Its success could well redefine not only the posture of the JASDF, but also the technological and geopolitical dynamics of the Asia-Pacific region.
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