Relationship dossier
United Kingdom
United States
Relationship assessment
A durable partnership spanning defense, intelligence, nuclear cooperation and economic policy
United Kingdom toward United States
+80The United Kingdom cooperates with the United States through NATO and Five Eyes intelligence-sharing arrangements, and maintains nuclear cooperation under the 1958 Mutual Defence Agreement. The 2023 Atlantic Declaration set out further bilateral work on economic security and emerging technologies.
United States toward United Kingdom
+80The United States cooperates with the United Kingdom through NATO and Five Eyes intelligence-sharing arrangements, and maintains nuclear cooperation under the 1958 Mutual Defence Agreement. The 2023 Atlantic Declaration set out further bilateral work on economic security and emerging technologies.
Overall relationship
+80The relationship is anchored by sustained defense and intelligence cooperation, a longstanding nuclear agreement, and recurring bilateral economic initiatives. This breadth and durability underpin a close partnership, while periodic differences over trade and policy do not outweigh the cooperative structure.
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
The United Kingdom and the United States maintain a close, durable partnership spanning defense, intelligence, nuclear cooperation and economic policy. Their governments cooperate through NATO and the Five Eyes intelligence partnership, and the 1958 Mutual Defence Agreement provides a lasting framework for nuclear cooperation. The 2023 Atlantic Declaration further set out bilateral cooperation on economic security and emerging technologies. Differences have occurred on trade and other policy issues, but the relationship remains substantially cooperative.
Key developments
The United Kingdom and the United States signed the Mutual Defence Agreement, establishing a framework for nuclear cooperation.
The governments announced the Atlantic Declaration, setting out bilateral cooperation on economic security, technology and trade.
Major uncertainties
- The extent and implementation of cooperation under newer economic and technology initiatives may change over time.
- The scope of intelligence-sharing arrangements is not fully public.