Overview
Although the United States remains Japan’s sole ally and the US-Japan alliance remains a cornerstone of regional security, this project evaluates Japan’s defence and security cooperation with European partners which has advanced significantly over the past decade. As Japan faces its harshest strategic environment since 1945, deepening defence and security ties with European powers has assumed greater significance. This now includes joint industrial collaboration on cutting-edge defence equipment such as the UK-Japan-Italy next generation Global Combat Aircraft Programme (GCAP). The Netherlands navy intends to deploy a frigate to the Indo-Pacific every two years, while two Royal Navy forward-deployed offshore patrol vessels regularly visit Japanese naval ports since 2021. British, Italian and French Carrier Strike Groups have exercised with Japan’s Maritime Self-Defense Forces, while European Eurofighter Typhoon and F-35 fighter aircraft now train in Japanese airspace. Meanwhile, 2025 marked a momentous year for Japan’s Self-Defense Forces’ debut in Europe. The Atlantic Eagles mission was a long-range deployment of F-15 fighter aircraft supported by refuelling tankers and transports for the first time ever to the United Kingdom and Germany. Japanese paratroopers also participated in a field training exercise for the first time ever on the European mainland, joining the Italy-led multi-national airborne Exercise Mangusta 2025.
The purpose of this project is to study multifaceted components of these cross-regional defence engagements. We analyse the strategies, motivations and capabilities of Japan and European defence partners, and the extent to which these developing partnerships complement the US-Japan alliance as well as serve dual purposes of deterrence and reassurance in the region.
This project gratefully acknowledges the support of entrusted research funding from the Embassy of the Kingdom of Netherlands in Japan; and Grant-in-Aid for Scientific Research (B) (No. 23K20585).