Sputnik crisis
Due to concerns over the buildup of Soviet missiles, US President Dwight D. Eisenhower met Prime Minister Harold Macmillan in Bermuda in March 1957 to explore the possibility of short-term deployment of IRBMs in the United Kingdom until the long-range intercontinental ballistic missiles (ICBMs) were deployed. The October 1957 Sputnik crisis caused this plan to be expedited. The first Thor missile arrived in the UK on a Douglas C-124 Globemaster II transport aircraft in August 1958, and was delivered to the RAF in September.