It took a string of defence ministers on both sides of the Pacific and a little more than two years, but the AIM-120 AMRAAM is finally getting a Japanese address. On Wednesday 28 October in Cebu, in the Philippines, Japan's Defense Minister Shinjiro Koizumi and US Secretary of Defense Pete Hegseth agreed to set up a final assembly and inspection facility for the missile in Japan.

Koizumi announced the deal at a press conference after the two men met for about half an hour on the sidelines of the ASEAN Defence Ministers' Meeting-Plus. The Pentagon's own readout of the meeting did not mention the plant at all. Tokyo, clearly, was the more excited party.

The Japan AMRAAM facility lands just weeks after the Pentagon handed RTX a multiyear AMRAAM contract worth up to 20.7 billion dollars. The United States wants more missiles, faster, from more places. Japan has just volunteered to be one of them.

“We finally reached an agreement”

Koizumi's choice of words told the story. The phrase “finally” is doing a lot of work in his statement, and for good reason. The project was launched at the US-Japan “2+2” security talks in Tokyo in July 2024, when the allies agreed to expand production of both the AMRAAM and the Patriot PAC-3 MSE interceptor.

He went further, calling it a groundbreaking agreement that would secure equipment for both countries and strengthen Japan's own defence industrial base. Hegseth, according to the Pentagon readout, welcomed Japan's efforts to strengthen its defence industrial capacity and promised close coordination on critical munitions production. Diplomatic translation: yes, please.

Where the plant will be built, who will run it and when the first Japanese-assembled missile will roll out have not been announced.

Why the Japan AMRAAM deal took so long

Japan does not do weapons co-production casually. Its post-war restrictions on arms exports and on building offensive weapons with allies have loosened in recent years, but every step still takes political effort. Air & Space Forces Magazine notes that the AMRAAM also carries classified guidance technology and intellectual property, which demanded safeguards before any of it could move to a Japanese production line.

Japan has done something like this before, in the other direction. In December 2023, Tokyo changed its export rules so that PAC-3 interceptors built in Japan under licence could be shipped to the United States to refill American stocks drained by the war in Ukraine. The AMRAAM deal follows the same logic: Japan as a second factory floor for American missiles.

Tokyo is also a big customer. In January 2025, the US State Department approved the sale of up to 1,200 AMRAAMs, AIM-120D-3s and C-8s, to Japan for an estimated 3.64 billion dollars. Assembling and checking at least some of them at home would shorten the supply line in a crisis.

The 1,900-missile question

The Japan AMRAAM deal makes most sense next to the numbers coming out of Tucson. In late September, the Pentagon and RTX announced a five-year AMRAAM contract with two option years, worth up to 20.7 billion dollars. The award, published by the US Air Force on 23 October, covers Lots 41 to 47, including AIM-120D-3 missiles with modernised processors.

WFAA reports on Raytheon's contract to ramp up AMRAAM production.

The contract itself does not specify quantities, but RTX says it will ramp annual production to at least 1,900 AMRAAMs. For perspective, US Air Force and Navy buys stayed at or below about 400 missiles a year between fiscal 2017 and 2022, according to Air & Space Forces Magazine. RTX says AMRAAM now serves more than 40 nations, and every one of them wants its order delivered yesterday.

A plant in Japan will not change those figures overnight. What it does is put a second assembly and test line inside the first island chain, next door to the F-35 that will fire the missiles. In a long war in the Pacific, the most valuable AMRAAM is the one that does not need to cross an ocean first.

Sources: Air & Space Forces Magazine, Jiji Press via Nippon.com, Financial News (citing Asahi Shimbun and NHK), RTX, Asian Military Review, Defence Connect, Indomiliter