Japan and the United States Agree to Establish AMRAAM Final Assembly in Japan

The agreement

Japan and the United States have agreed to establish a facility in Japan for the final assembly and check-out of the AIM-120 Advanced Medium-Range Air-to-Air Missile (AMRAAM), a step that would extend Japan's planned role in the missile's production beyond components to its final stage.

What the ministers agreed

The agreement was reached on 28 October by Japanese Defense Minister Koizumi Shinjiro and U.S. Secretary of War Pete Hegseth, who met for about 30 minutes in the Philippines on the sidelines of the ASEAN Defence Ministers' Meeting Plus (ADMM-Plus). According to Japan's Ministry of Defense summary of the talks, the two also agreed to share the technical information needed to increase production of the SM-3 Block IIA interceptor.

The ministry's Japanese-language summary records the AMRAAM decision as an agreement to establish (設置) a facility in Japan for final assembly and inspection (最終組立・検査). The U.S. Department of War's readout, dated 27 October, does not mention either missile agreement. On defense production, it says only that Hegseth welcomed Japan's efforts to strengthen its defense industrial capacity and that the two committed to continue close coordination on critical munitions production.

Japan's summary places both decisions under Koizumi's follow-up on "Operation Supercharge," which the ministry describes as an initiative to further accelerate bilateral cooperation on defense equipment and technology. Koizumi also stressed the importance of cooperation on naval vessels. The rest of the meeting covered air and missile defense, expanded joint training, aircraft dispersal, wider access to facilities, a stronger allied presence in southwestern Japan, cyber cooperation and base issues on Okinawa. The missile decisions were the meeting's clearest production-related steps.

An April possibility becomes a commitment

October's decision advances an issue the allies had left open in April. At the fourth Japan-U.S. Defense Industrial Cooperation, Acquisition, and Sustainment (DICAS) plenary, held in Washington on 14 April, a Missile Co-production Working Group reported on the co-development and co-production of missiles that the two governments had agreed to pursue at a defense ministerial meeting in January and a leaders' summit in March. Drawing on a feasibility study conducted with Mitsubishi Electric and Raytheon, the two sides identified circuit-card assembly as part of the scope of AMRAAM co-production and agreed to further discuss the possibility of final assembly and check-out in Japan. The plenary also agreed to upgrade DICAS into an enhanced "DICAS 2.0" framework, restating a shared goal of producing defense equipment "more rapidly and at a greater scale."

Two weeks later, Mitsubishi Electric said it would move forward with discussions with industry partners, including Raytheon, on the scope of Japan's participation: circuit-card work and "the possibility of a future" final assembly and check-out in Japan. The company said it had been studying whether it could contribute to AMRAAM production under contracts with the Ministry of Defense in 2024 and 2025, and described the missile as currently manufactured in the United States. It cited its experience developing and manufacturing air-to-air missiles for the ministry, but it did not identify itself as the future assembler.

The SM-3 agreement builds on an effort already under way. In April, the allies confirmed measures intended to raise SM-3 Block IIA production roughly fourfold and agreed to assess further acceleration and expansion. Neither April's nor October's account says how much output has actually increased.

April's agenda also included a third missile. On potential co-production of the PAC-3 MSE interceptor, the two sides agreed to accelerate consideration of concrete measures to improve production efficiency. Neither October summary mentions the PAC-3. That silence does not show the effort has stalled, since the summaries are selective accounts of a 30-minute meeting, but it leaves the October commitments covering two of the three missiles named in April.

A final stage with no site yet

The AMRAAM decision is the larger change to the planned division of production work. In April, the allies identified circuit-card assembly as part of the scope of co-production. October's agreement extends the planned scope to the final stage. Final assembly and check-out turns components into a completed missile for testing before delivery; if the facility is established, that stage would take place in Japan.

The ministers agreed to establish a facility; they did not announce one that is already operating. Neither language version of Japan's summary names a site, operator, contract, schedule or output target, and the U.S. readout does not mention the facility. Those details will show how much new capacity the facility could create and whether any existing U.S. final-assembly work would shift to Japan. For now, the agreement is a political commitment whose industrial form remains undefined.

For AMRAAM, the next indicators are a named site or operator for the facility, a contract or budget line, and the outcome of the next DICAS plenary. For SM-3, the question is whether either government reports technical information being shared under the October agreement and whether further production increases follow. For the PAC-3 MSE, it is whether the production-efficiency work discussed in April reappears in either government's account.