The Cuban Missile Crisis, also known as the October Crisis was a 13 day confrontation between the USSR and USA. The USSR was attempting to place nuclear warheads in Cuba after finding American Weapons in Turkey and the Bay of Pigs invasion. A blockade was set up by the American Navy that was designed to shoot at the ships if they passed a set boundary. JFK was essentially threatening World War 3 over the weapons. The USSR agreed to leave as long as the US never invade Cuba without reason, and the USSR would also dismantle its warheads in Cuba. It is the closest to world war 3 some would say the world has ever seen.