The missiles in Cuba were discovered by a U-2 spyplane taking surveillance photos. These images were analyzed by photo interpreters at the National Photographic Interpretation Center, and it was discovered that there were medium range nuclear missiles based outside of the town of San Cristobal. Before they were detected by spy-planes, the missiles were installed for 5 weeks.
Mini Video: U2 Spyplane
~John F. Kennedy, Address During the Cuban Missile Crisis
After the discovery of missiles in Cuba, the United States began to formulate a response. The top generals within ExComm (A committee created by Kennedy during the crisis, Executive Committee of The National Security Council) were mixed on U.S. response. Many advocated for an immediate invasion of Cuba, while others suggested airstrikes to destroy the missiles before they became operational. Finally, Kennedy decided on a more diplomatic approach. On October 22, 1962, Kennedy announced to the nation his decision. Cuba would be put under a blockade, which Kennedy referred to as a “quarantine.” Any vessels approaching Cuba carrying weapons or missiles would be stopped, turned around, and surveillance of Cuba would be heightened. Finally, Kennedy reiterates that the Soviet government has repeatedly lied about missile presence, and this offense would not be taken lightly. On the Russian side, Khrushchev's policies were unpopular. Many believed he was too soft, and was giving up too much. However, both sides comes to the realization that any attack or invasion of Cuba could easily lead to a full scale nuclear war. Both sides are conscious of this throughout the debates.