 Where before combat in the air would have been between aircraft, with high flying bombers carrying nuclear weapons and fast interceptor fighter aircraft trying to stop them, now the guided missile, particularly the surface-to-air missile, threatened all aircraft.The emergent space age showed that missiles could also deliver those nuclear weapons anywhere in the world.UK war plans of the 1950s were based on a "three-day war", in which the Warsaw Pact's forces would begin with a conventional attack in Europe, but the war would quickly progress to the use of tactical nuclear weapons.