US–UK Mutual Defence Agreement

The US–UK Mutual Defense Agreement, or the 1958 UK–US Mutual Defence Agreement, is a bilateral treaty between the United States and the United Kingdom on nuclear weapons co-operation. The treaty's full name is Agreement between the Government of the United States of America and the Government of the United Kingdom of Great Britain and Northern Ireland for Cooperation on the uses of Atomic Energy for Mutual Defense Purposes.

Source: Wikipedia — US–UK Mutual Defence Agreement (CC BY-SA 4.0)