The Cuban missile crisis was a 13-day long standoff between America and the Soviet Union, when ballistic missiles were discovered in Cuba by an American U2-spy plane that traveled at a high altitude over the Caribbean island.
The espionage occurred during the height of the Cold War between the USA and the Soviet Union, which was a series of non-violent clashes in politics and economy.
Soviet think tanks had decided to store the missiles in Cuba for two main reasons: to deter any further aggression from the USA (feared due to an earlier Bay of Pigs conflict in 1961) against Cuba and by offering a strategic missile arsenal to hold up against countries in Turkey and Western European nations that were against the USSR.
Due to the proximity (90 miles) between Cuba and the Southern portion of USA, the missile act was considered an outward threat towards the peace of the region.
President John F. Kennedy decided to consult trusted advisers from his executive committee, or ExCom, who discussed pragmatic ways to respond to the worrying aerial report.
After some consideration, the Kennedy administration decided that a naval blockade was to be set up against Cuba in hopes of forcing a surrender of arms. Additionally, the US was determined to use military force if necessary.
Thankfully, history narrowly avoids what would have been a catastrophic nuclear situation when then soviet leader Nikita Khrushchev proposed removal of the Cuban missiles in exchange for the Americans agreeing to avoid an invasion of Cuba.
President Kennedy took up the offer and both nations settled the conflict through diplomatic means, but many historians would agree that the nerve-wracking event was a close shave and could have led the world toward another world war or even global destruction.