Page "Harold Macmillan" Paragraph 55

On 25 March 1957 Macmillan acceded to Eisenhower's request to base 60 Thor IRBMs in England under joint control, to replace the nuclear bombers of the Strategic Air Command, which had been stationed under joint control in the country since 1948, and were approaching obsolescence.

Partly as a consequence of this favour, in late October 1957, the US McMahon Act was eased to facilitate nuclear co-operation between the two governments, initially with a view to producing cleaner weapons and reducing the need for duplicate testing.

The Mutual Defence Agreement followed on 3 July 1958, speeding up British ballistic missile development, notwithstanding unease expressed at the time about the impetus co-operation might give to atomic proliferation by arousing the jealousy of France and other allies.