The use of atomic bombs during World War II led to an arms race between the United States and the Soviet Union. After President Truman ordered the bombings of Nagasaki and Hiroshima, the world learned of the devastating power inherent in a nuclear bomb. Threatened by the United State's strategic advantage, the Soviet Union ramped up efforts to match America's nuclear potential. By the end of the 1950s, the Soviet Union had developed the first Intercontinental Ballistic Missile, leading the anxiety of the 1960s as seen in the Cuban Missile Crisis. The arms race would continue into the 1980s.
