The 1963 Cabinet Papers / Polaris: Ministers discussed all-British nuclear deterrent

A 'HOME-MADE' independent nuclear deterrent, designed and built in Britain without American help, was contemplated by Harold Macmillan in the event of negotiations with the US on Polaris breaking down in the winter of 1962-63.

A 'Top Secret' minute sent on Boxing Day 1962 by the prime minister to Peter Thorneycroft, Minister of Defence, seeks advice on that idea, warning that 'there are a lot of snags to be watched very carefully' in securing a formal Polaris agreement with President Kennedy's administration.

A small meeting of senior ministers, under Macmillan's chairmanship, considered in detail the proposal for a British deterrent. However, the Foreign Office dismissed the idea as impractical because of the expense and Britain's lack of technological expertise.

The minute - one of a cluster sent by Macmillan as the final year of his premiership was about to begin - shows the prime minister in sombre mood despite his acclaimed success in negotiations with JFK at Nassau earlier in the month. The summit agreed in principle a cut- price Polaris deal under which the US would make the missile and Britain the warheads.

But Macmillan warned Thorneycroft that the UK was still vulnerable to US pressure which could come to a point 'where we would threaten to tear up the agreement'. He added: 'For this purpose could you find out from the Minister of Aviation or anybody else whether, if we were driven into a corner, we could either as a bluff or as a reality make a Polaris missile, perhaps of a simpler kind, ourselves from our own designs; how long would it take etc.?'

But Macmillan - perhaps sensibly, given the eventual success of the negotiations - kept his deepest doubts to himself when he reported to the Cabinet on Nassau in January. Nor did he share with his colleagues a secret understanding which he had first with President Eisenhower, and then reinforced with Kennedy in Nassau, that neither country would use its deterrent without consulting the other. Nevertheless, his account warned of the strains in the alliance.

Cabinet minutes report him as saying: 'The US administration includes hardly any of the men who had been associated with this country in the Second World War. Many of President Kennedy's advisers were inclined to indulge an inflated conception of the material power at the disposal of their government'.