Japan and the United Kingdom Are Preparing for Great Power Competition

Japan and the United Kingdom Are Preparing for Great Power Competition

The release of the Japan-UK Accord means that defense and security cooperation has extended to the entire society of both countries.


Since the beginning of the 2010s, the United Kingdom has developed its Indo-Pacific policy in pursuit of economic opportunities and expanding its security engagement. As part of these initiatives, Japan and the UK have developed defense and security cooperation since April 2012, when Japanese prime minister Yoshihiko Noda and British prime minister David Cameron issued the Joint Statement: A Leading Strategic Partnership for Global Prosperity and Security.

Against this background, on May 18, 2023, British prime minister Rishi Sunak, who was in Japan to attend the G7 Summit, issued the Hiroshima Accord: an Enhanced Japan-UK Global Strategic Partnership with Japanese prime minister Fumio Kishida. The Japan-UK Hiroshima Accord, a comprehensive agreement on bilateral cooperation in the field of defense and technology, is a milestone for further enhancement of the bilateral defense and security cooperation that has been strengthened over the past decade or more.


The Japan-UK Hiroshima Accord indicated the development of cooperation among defense authorities based on the Japan-UK Reciprocal Access Agreement that was signed in January 2023. In the accord, both countries will conduct more practical joint military exercises to improve interoperability between the Japan Self-Defense Forces and the British Armed Forces, including the future redeployment of the UK’s aircraft carrier strike group to the Indo-Pacific.

It is also noteworthy that the accord positioned Japan-UK defense cooperation within multilateral frameworks such as the Free and Open Indo-Pacific (FOIP) initiative and the Euro-Atlantic and Indo-Pacific Partnership. On March 13, 2023, the UK released a new foreign and security policy paper, “Integrated Review Refresh 2023: Responding to a more contested and volatile world” (IR23), with an eye on rising China. In it, the UK positioned its Indo-Pacific policy as “a permanent pillar of the UK’s international policy” in the context of the Japan-led FOIP and the NATO-led Euro-Atlantic and Indo-Pacific partnerships. Such a British Indo-Pacific policy in IR23 was also reflected in the Japan-UK Hiroshima Accord.

However, in the history of Japan-UK defense and security cooperation, the two countries have consistently pursued cooperation in the field of defense equipment and technology. Of the eight defense and security cooperation items agreed upon in the 2012 Japan-UK Joint Statement, three were related to defense equipment and technology. On this basis, Japan concluded an Agreement for the Transfer of Defense Equipment and Technology with the UK in July 2013. Within this framework, Japan and the UK promoted defense equipment and technology cooperation, culminating in the announcement of the Joint Leaders' Statement on the Global Combat Air Program (GCAP), a Japan-UK-Italy joint development plan for fighter aircraft, in December 2022.

On the other hand, given the importance of economic security in the face of intensifying great power competition, the Japan-UK Hiroshima Accord included a section entitled “Economic Prosperity and Security Underpinned by Science, Technology and Innovation,” which called for the establishment of a more comprehensive science and technology cooperation framework beyond purely defense technology. To do so, that section announces the establishment of a Ministerial Dialogue Framework between Japan’s Ministry of Economy, Trade, and Industry (METI) and the UK’s Department for Business and Trade (DBT) to facilitate comprehensive cooperation between Japan and the UK in the areas of supply chain resilience, access to critical natural resources, semiconductors, digital data, AI, and health sciences.

The accord also states that these efforts will be facilitated by “a new Industrial Science, Innovation and Technology Implementing Arrangement” that will include not only relevant ministries but also the private sector, education, and research institutions. A press release issued by Sunak on May 17, 2023, the day before the launch of the Japan-UK Hiroshima Accord, announced the deployment of an aircraft carrier strike group to the Indo-Pacific in 2025 and also noted the strategic relationship between Imperial College London and the University of Tokyo, as well as technical cooperation with Japanese private companies such as Hitachi Ltd. and Fujitsu. These remarks suggest that the development of bilateral cooperation on industrial science, technology, and innovation has already made considerable progress.

Thus, the Japan-UK Hiroshima Accord is a joint declaration by Japan and the UK on the efforts to prepare for the irreversible reorganization of global supply chains and international joint research networks in the context of economic security under great power competition. In other words, the release of the Japan-UK Accord means that defense and security cooperation has gone beyond the framework of diplomatic and defense authorities to reach a stage where it extends to the entire society of both countries.

Shingo Nagata is a visiting researcher at the Institute of Human and Social Sciences, Kanazawa University, Japan. He also serves as an editorial board member of the Japan Society of Strategic Studies.

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