The Cuban Missile Crisis was a confrontation between the United States, the Soviet Union, and Cuba during the Cold War. In Russia, it is termed the " Caribbean Crisis ," (Russian: Карибский кризис , Karibskiy krizis ) while in Cuba it is called the " October Crisis ." The crisis ranks with the Berlin Blockade as one of the major confrontations of the Cold War, and is often regarded as the moment in which the Cold War came closest to a nuclear war.

The climax period of the crisis began on October 8, 1962. Later on October 14 United States reconnaissance photographs taken by an American U-2 spy plane revealed missile bases being built in Cuba. The crisis ended two weeks later on October 28, 1962, when President of the United States John F. Kennedy and United Nations Secretary-General U Thant reached an agreement with the Soviets to dismantle the missiles in Cuba in exchange for a no invasion agreement and a secret removal of the Jupiter and Thor missiles in Turkey.

Kennedy, in his first public speech on the crisis, given on October 22 1962, gave the key warning,

It shall be the policy of this nation to regard any nuclear missile launched from Cuba against any nation in the Western Hemisphere as an attack on the United States, requiring a full retaliatory response upon the Soviet Union.

This speech included other key policy statements, beginning with:

To halt this offensive buildup, a strict quarantine on all offensive military equipment under shipment to Cuba is being initiated. All ships of any kind bound for Cuba from whatever nation and port will, if found to contain cargoes of offensive weapons, be turned back. This quarantine will be extended, if needed, to other types of cargo and carriers. We are not at this time, however, denying the necessities of life as the Soviets attempted to do in their Berlin blockade of 1948.

He ordered intensified surveillance, and cited cooperation from the foreign ministers of the Organization of American States (OAS). Kennedy "directed the Armed Forces to prepare for any eventualities; and I trust that in the interest of both the Cuban people and the Soviet technicians at the sites, the hazards to all concerned of continuing the threat will be recognized." He called for emergency meetings of the OAS and United Nations Security Council to deal with the matter. In Havana, there was fear of military intervention by the United States in Cuba. In April 1961, the threat of invasion became real when a force of CIA-trained Cuban exiles opposed to Castro landed at the Bay of Pigs. The invasion was quickly terminated by Cuba's military forces. Castro was convinced the United States would invade Cuba. Shortly after routing the Bay of Pigs Invasion, Castro declared Cuba a socialist republic, established formal ties with the Soviet Union, and began to modernize Cuba's military.

The United States feared any country's adoption of communism or socialism, but for a Latin American country to openly ally with the USSR was regarded as unacceptable, given the Russo-American enmity dating from the end of the Second World War in 1945.

In late 1961, Kennedy engaged Operation Mongoose, a series of covert operations against Castro's government which were to prove unsuccessful.. More overtly, in February 1962, the United States launched an economic embargo against Cuba.

The United States also considered direct military attack. Air Force Gen. Curtis Lemay presented to Kennedy a pre-invasion bombing plan in September, while spy flights and minor military harassment from the United States Guantanamo Naval Base were the subject of continual Cuban diplomatic complaints to the U.S. government.

By September 1962, Cuban observers fearing an imminent invasion would have seen increasing signs of American preparations for a possible confrontation, including a joint Congressional resolution authorizing the use of military force in Cuba if American interests were threatened, and the announcement of an American military exercise in the Caribbean planned for the following month (Operation Ortsac).