The Nassau Agreement, concluded on 21 December 1962, was an agreement negotiated between President of the United States, John F. Kennedy, and Harold Macmillan, the Prime Minister of the United Kingdom, to end the Skybolt Crisis. A series of meetings between the two leaders over three days in the Bahamas followed Kennedy's announcement of his intention to cancel the Skybolt air-launched ballistic missile project. The US agreed to supply the UK with Polaris submarine-launched ballistic missiles for the UK Polaris programme.
Under an earlier agreement, the US had agreed to supply Skybolt missiles in return for allowing the establishment of a ballistic missile submarine base in the Holy Loch near Glasgow. The British Government had then cancelled the development of its medium-range ballistic missile, known as Blue Streak, leaving Skybolt as the basis of the UK's independent nuclear deterrent in the 1960s. Without Skybolt, the V-bombers of the Royal Air Force (RAF) were likely to have become obsolete through being unable to penetrate the improved air defences that the Soviet Union was expected to deploy by the 1970s.
At Nassau, Macmillan rejected Kennedy's other offers, and pressed him to supply the UK with Polaris missiles. These represented more advanced technology than Skybolt, and the US was not inclined to provide them except as part of a Multilateral Force within the North Atlantic Treaty Organization (NATO). Under the Nassau Agreement the US agreed to provide the UK with Polaris. The agreement stipulated that the UK's Polaris missiles would be assigned to NATO as part of a Multilateral Force, and could be used independently only when "supreme national interests" intervened.
The Nassau Agreement became the basis of the Polaris Sales Agreement, a treaty which was signed on 6 April 1963. Under this agreement, British nuclear warheads were fitted to Polaris missiles. As a result, responsibility for Britain's nuclear deterrent passed from the RAF to the Royal Navy. The President of France, Charles de Gaulle, cited Britain's dependence on the United States under the Nassau Agreement as one of the main reasons for his veto of Britain's application for admission to the European Economic Community (EEC) on 14 January 1963.