The Czechoslovakia plan was approved on 14 October 1964, the day Soviet leader Nikita Khrushchev was overthrown, and after the Prague Spring in 1968 the Soviets had to completely remove the Czech military from its plans. By the late 1960s they moved to a war strategy that lessened the dependence on nuclear weapons, resembling the West's flexible response. Warsaw Pact plans continued to assume, however, that NATO would make a surprise attack which it would repulse into the west; the East Germans even prepared occupation currency and new street signs.