What did U-2 spy planes discover in 1962 that might have caused a nuclear war?

In 1962, U-2 spy planes discovered Soviet nuclear missile installations in Cuba, which had the capability to strike the United States within minutes. This revelation led to a major confrontation between the U.S. and the Soviet Union, known as the Cuban Missile Crisis. The discovery heightened tensions and brought the two superpowers to the brink of nuclear war, as the U.S. demanded the removal of the missiles and imposed a naval blockade around Cuba. Ultimately, the crisis was resolved through negotiations, but it marked a significant moment in Cold War history.