With the introduction to service of long-range bombers and intercontinental ballistic missiles, the need for a SAC presence in the UK diminished, On 3 April 1964, the last SAC aircraft, a B-47 from the 380th Bombardment Wing, left RAF Brize Norton, ending nearly 12 years' of continual B-47 deployments, and the 7th Air Division on 30 June 1964. The tactical nuclear weapons remained. In the 1970s, up to 60 F-111s based in the UK were on quick reaction alert, each carrying multiple B61 nuclear bombs. About 70 F-111s were based in the UK from 1971. In 1977, the Labour government gave permission for another 90 to be deployed. During the 1980s nuclear armed USAF Ground Launched Cruise Missiles (GLCMs) were deployed at RAF Greenham Common and RAF Molesworth, as a consequence of the 1979 NATO Double-Track Decision, under which NATO countries agreed to modernise the alliance's nuclear weapons.