After the end of the Berlin crisis, Kennedy was optimistic that the worst of his dealings with the Soviets was finally over. He thought Khrushchev wanted peace. However, when the Soviet Union moved missiles and troops into Cuba, Kennedy realized he had been gravely mistaken. With Cuba so close to the United States, he knew he had to handle the situation carefully. Any misstep would result in his worst fear — a nuclear war with the Soviet Union. For thirteen days in October 1962, the world watched two superpowers face off.