 In 1961 and 1962, at the height of the Cold War, about 50,000 women brought together by Women Strike for Peace marched in 60 cities in the United States to demonstrate against nuclear weapons.In 1963, many countries ratified the Partial Test Ban Treaty which prohibited atmospheric nuclear testing.Some local opposition to nuclear power emerged in the early 1960s, and in the late 1960s some members of the scientific community began to express their concerns.