The most significant turning point in the Cold War was the Cuban Missile Crisis, tensions between both sides decreased after both sides realized the risk of starting a nuclear war. The Soviet union provision of ballistic missiles to Cuba led to the most dangerous Cold War confrontation between the United States and the Soviet Union and brought the world to the brink of nuclear war. The two superpowers soon signed the Nuclear Test-Ban Treaty of 1963, which banned aboveground nuclear weapons testing. Premier Nikita Khrushchev ordered withdrawal of missiles from Cuba, ending the Cuban Missile Crisis.