On 28 October Defence Minister Koizumi met US Secretary of War Hegseth in Cebu, the Philippines, on the margins of the ADMM-Plus, and the two agreed to strengthen cooperation so that the recent wave of cyberattacks at home and abroad does not seriously affect citizens' lives, economic activity and security in Japan and the United States. Koizumi explained Japan's intention to strengthen 'denial defence' capabilities ahead of the year-end revision of the three security documents, and the ministers agreed to establish a final assembly and inspection facility for the AIM-120 AMRAAM in Japan.
Cyber harm prevention reaches the alliance agenda
The meeting came two days after Japan's first ministerial meeting on cybersecurity, bringing the domestic wave of large-scale data breaches onto the alliance agenda. As reported from the Ministry of Defense's briefing, the two agreed to strengthen cooperation aimed at preventing the cyberattacks occurring at home and abroad from seriously affecting the lives of citizens, economic activity and security in Japan and the United States. The reporting available carries no detail on mechanisms such as information-sharing channels, links to active cyber defence or early-warning arrangements with AI companies. The significance therefore lies in cyber harm prevention being confirmed as a formal item between the two defence establishments.
'Denial defence' and the First Island Chain
Koizumi briefed Hegseth on the year-end revision of the three security documents and conveyed Japan's intention to strengthen 'denial defence' capabilities that would deter unilateral changes to the status quo by force or coercion (Jiji Press, citing the Ministry of Defense). According to AFP's account of the US readout, the two discussed the need to implement 'an effective denial defence in the First Island Chain' and committed to continued 'close coordination' on the production of critical munitions. They also agreed to pursue more advanced and realistic bilateral training, including further live-fire exercises. On defence spending, reports that the US side raised it coexist with reports that no figures were discussed, so confirmation awaits the ministry's summary of the meeting.
AMRAAM final assembly in Japan: an agreement two years in the making
The ministers agreed to establish a final assembly and check-out (FACO) facility for the AIM-120 AMRAAM in Japan. Koizumi reportedly called it 'a groundbreaking agreement' at his press conference and described the missile as essential for the F-35. The effort began in July 2024 under both ministers' predecessors and reached formal agreement after about two years. The facility's location, operator, production volume and start date are unpublished; the US readout did not mention AMRAAM directly and said only that Hegseth welcomed Japan's efforts to strengthen its defence industrial capacity. How Japanese-assembled air-to-air missiles will be folded into the alliance's munitions supply chain is the next item to be disclosed.
Sources
Primary sources
- 1
防衛大臣記者会見（2026年10月28日）
Ministry of Defense of Japan · External site
Reporting
- 2
国民の生活などへの深刻な影響を防ぐ サイバー攻撃の被害防止めぐり日米防衛トップが連携強化で一致
Source checked 29 Oct 2026
TBS NEWS DIG · External site - 3
Japan Tells U.S. of Plans to Boost Denial Defense Capabilities
Source checked 29 Oct 2026
時事通信（nippon.com） · External site - 4
US and Japan Finalize Agreement for AMRAAM Facility
Source checked 29 Oct 2026
Air & Space Forces Magazine · External site - 5
Hegseth proposes 'ambitious' US-Asean defense framework at Philippine summit
Source checked 29 Oct 2026
Manila Times（AFP） · External site
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AI & Security Observatory（2026-10-28）「日米防衛相会談、サイバー被害防止の連携強化とAMRAAM国内最終組立で合意 「拒否する防衛力」を説明」『AI & Security Observatory』、第1.0版、最終更新2026-10-29。https://ai-security-observatory.org/ja/brief/brief-20261029-01/
AI & Security Observatory (2026-10-28). Japan–US defence ministers agree to deepen cyber cooperation and set up an AMRAAM final-assembly facility in Japan . AI & Security Observatory, version 1.0. Updated 2026-10-29. https://ai-security-observatory.org/en/brief/brief-20261029-01/
Version 1.0 · Publication date 28 Oct 2026 · Updated 29 Oct 2026
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