Relationship dossier
Japan
United Kingdom
Relationship assessment
Japan and the United Kingdom sustain a close partnership spanning defense, technology, and trade.
Japan toward United Kingdom
+75Japan has pursued substantive security and technology cooperation with the United Kingdom, including the Reciprocal Access Agreement and the joint Global Combat Air Programme. The two governments also set out a broad strategic partnership in 2023.
United Kingdom toward Japan
+75The United Kingdom has pursued substantive security and technology cooperation with Japan, including the Reciprocal Access Agreement and the joint Global Combat Air Programme. The two governments also set out a broad strategic partnership in 2023.
Overall relationship
+75The relationship is underpinned by enduring economic ties and an expanding strategic partnership. The Reciprocal Access Agreement, joint fighter development, and the 2023 strategic accord demonstrate sustained cooperation across defense, technology, and broader policy.
How to read these scores
Scores are rough judgments, not objective measurements or current verification. Directional scores describe government policy and conduct, not public opinion. The overall score is an independent estimate, never an average.
- −100
- Extreme sustained hostility
- −50
- Substantially adversarial
- 0
- Mixed or neutral, supported by knowledge
- +50
- Substantially cooperative
- +100
- Exceptionally close sustained partnership
“Not assessed” means there is no recorded score. Pair existence makes no claim about diplomatic recognition or established relations.
Relationship context
Overview
Japan and the United Kingdom maintain a close strategic partnership, supported by defense cooperation, reciprocal access for armed forces, and collaboration on a next-generation fighter programme. The two governments also concluded a broad strategic agreement in 2023 and have a bilateral economic partnership agreement. These arrangements give the relationship substantial and sustained cooperation across security, technology, and trade.
Key developments
Japan and the United Kingdom signed a Reciprocal Access Agreement to facilitate cooperation between their armed forces.
The United Kingdom and Japan announced the Global Combat Air Programme with Italy to develop a next-generation combat aircraft.
Japan and the United Kingdom issued the Hiroshima Accord, setting out an enhanced strategic partnership.
The Reciprocal Access Agreement between Japan and the United Kingdom entered into force.
Major uncertainties
- The extent and implementation of future defense and technology cooperation may evolve.