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Sale of Trident I Missiles to the United Kingdom Exchange of Letters Between the President and Prime Minister Margaret Thatcher of the United Kingdom.

July 14, 1980

Dear Madame Prime Minister:

In reply to your letter of July 10, 1980, I am pleased to confirm that the United States attaches significant importance to the nuclear deterrent capability of the United Kingdom and to close cooperation between our two Governments in maintaining and modernizing that capability. To further that objective, the United States is prepared to supply the United Kingdom TRIDENT I missiles, equipment and supporting services, as you propose in your letter, subject to and in accordance with applicable United States laws and procedures.

I view as important your statements that the POLARIS successor force will be assigned to NATO and that your objective is to take advantage of the economies made possible by our nuclear cooperation to reinforce your efforts to upgrade the United Kingdom's conventional forces. As you know, I regard the strengthening of NATO's conventional and nuclear forces as of highest priority for Western security.

I agree that as the next step in implementing these agreed arrangements, our two Governments should initiate the technical and financial negotiations which you propose.



[The Right Honorable Margaret R. Thatcher, M.P., Prime Minister, London]

10 July 1980

Dear Mr. President,

As you are aware the United Kingdom Government attaches great importance to the maintenance of a nuclear deterrent capability. It will be necessary to replace the present Polaris force in the early 1990's, and having reviewed the options, the Government has concluded that the Trident I weapon system best meets the need to maintain a viable nuclear deterrent capability into the 21st century. I write therefore to ask you whether the United States Government would be prepared, in continuation of the cooperation which has existed between our Governments in this field since the Polaris Sales Agreement of 6 April 1963, to supply on a continuing basis, Trident I missiles, equipment and supporting services, in a manner generally similar to that in which Polaris was supplied.

The United Kingdom Government would wish to purchase sufficient missiles, complete with multiple independently targettable re-entry vehicles and less only the warheads themselves, together with equipment and supporting services, on a continuing basis to introduce and maintain a force of 4 British submarines (or 5 if the United Kingdom Government so prefer), close coordination being maintained between the Executive Agencies of the two Governments in order to assure compatibility of equipment.

The successor to the Polaris force will be assigned to the North Atlantic Treaty Organisation, like the Polaris force; and except where the United Kingdom Government may decide that supreme national interests are at stake, the successor force will be used for the purposes of international defence of the Western alliance in all circumstances. It is my understanding that cooperation in the modernization of the United Kingdom nuclear deterrent in this way would be consistent with the present and prospective international obligations of both parties.

In particular, I would like to assure you that the United Kingdom Government continues to give whole-hearted support to the NATO Long-Term Defence Programme and to other strengthening of conventional forces. The United Kingdom Government has substantially increased its defence spending, in accordance with NATO's collective policy, and plans to make further such increases in the future in order to improve the effectiveness of its all-round contribution to Allied deterrence and defence. In this regard the objective of the United Kingdom Government is to take advantage of the economies made possible by the cooperation of the United States in making the Trident I missile system available in order to reinforce its efforts to upgrade its conventional forces.

If the United States Government is prepared to meet this request, I hope that as the next step the United States Government will be prepared to receive technical and financial missions to pursue these matters, using the framework of the Polaris Sales Agreement where appropriate.

Yours sincerely


[The President of the United States of America]

Note: The text of the letters was released on July 15. The White House press release also includes the letters exchanged by Secretary of Defense Harold Brown and Secretary of State Francis Pym of the United Kingdom.

Jimmy Carter, Sale of Trident I Missiles to the United Kingdom Exchange of Letters Between the President and Prime Minister Margaret Thatcher of the United Kingdom. Online by Gerhard Peters and John T. Woolley, The American Presidency Project https://www.presidency.ucsb.edu/node/250722

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