ISSUE AREAS:

US-UK Nuclear Cooperation

1958 US-UK Mutual Defence Agreement

The 1958 Mutual Defence Agreement is a bilateral treaty between the US and the UK on nuclear weapons cooperation. It covers all aspects of nuclear weapons design, development and maintenance. Under this unique agreement, the US and the UK exchange classified information with the objective of improving each party's "atomic weapon design, development, and fabrication capability". Although the US has nuclear cooperation agreements with a range of other countries, including France and those NATO countries that participate in nuclear sharing arrangements, the US-UK agreement is the most comprehensive by far.

The Agreement covers development of defence plans; training personnel in the use and defence against nuclear weapons; evaluation of enemy capabilities; development of nuclear delivery systems; and research, development and design of military reactors. The agreement also provides for the transfer of special nuclear material (i.e. plutonium or highly enriched uranium), components, and equipment between the two countries.

The UK depends heavily on US assistance to maintain and develop its nuclear arsenal, raising questions about whether this level of cooperation is in breach of the Nuclear Non-Proliferation Treaty.

Further information on the Mutual Defence Agreement is available here:

Latest News

• Leading lawyers say US-UK nuclear collaboration breaches international law, News Advisory from British American Security Information Council, the Acronym Institute for Disarmament Diplomacy and Peacerights, 26 July 2004
• Legal Opinion by Rabinder Singh QC and Professor Christine Chinkin, Matrix, 20 July 2004
• 1958 Mutual Defence Agreement, full text of the US-UK nuclear cooperation agreement

BASIC Publications

• US-UK nuclear weapons collaboration under the Mutual Defence Agreement: Shining a torch on the darker recesses of the ‘special relationship’, BASIC Press Release, 16 June 2004.
• US-UK nuclear weapons collaboration under the Mutual Defence Agreement: Shining a torch on the darker recesses of the ‘special relationship’, (PDF), by Nigel Chamberlain, Nicola Butler and Dave Andrews, BASIC Special Report 2004.3, 17 June 2004.
• Nuclear proliferation under the 'special relationship', BASIC Press Release, 23 April 2004
• Time to put Article I under the Spotlight, BASIC NPT Briefing, April 2004

Official Documents

• 1958 Mutual Defence Agreement and previous amendments, official text, June 21, 2004 (pdf)
• 2004 Amendment and supporting documents, June 21, 2004