Operation Anadyr was the secret Soviet Russia operation carried out in 1962 to place medium range and intermediate range missiles and nuclear warheads in Cuba during the Cold War, which led to the Cuban Missile Crisis. The mission was motivated by the fear of Nikita Khrushchev, First Secretary of the Communist Party of the Soviet Party, that the United States had a distinct advantage in ability to strike first because of US missiles positioned in Turkey, prompting him to convince Cuban leader Fidel Castro to let the Soviets deliver and set up the missiles in Cuba. Castro believed the missiles to be a deterrent to the imminent threat of another US invasion in the wake of the Bay of Pigs.
In order to keep the mission as secret as possible, the Soviets went to great lengths. To find an attempt to deceive, one doesnt have to look further than the name of the mission: Anadyr. Anadyr is the both the name of a river that feeds into the Bering Sea and the name of a Soviet bomber base and city in the far Russian north. The misnomer was meant to obscure, from both American communication interceptions and Russian military alike, the actual location of the mission. Furthermore, the Soviets loaded and unloaded the military cargo and military personnel, they did so only under darkness.  And only five Soviet officers knew the details of the operations and planned - handwritten - the entire operation themselves to protect against the leak of information, despite an operation of the magnitude typically requiring hundreds of individuals working for several weeks.  Even the soldiers and the captains of the 86 transport ships were deceived. The soldiers were told to pack ski boots and parkas, while the captains were not told their true destination until they were out at sea.
Three types of missiles were planned to be sent to Cuba during Operation Anadyr: R-12, R-14, and FKR-1. The R-12 was a medium range missile with the capability to hit Washington DC from Cuba, while the R-14 was an intermediate range missile with the ability to reach nearly the entire contiguous United States except the far reaches of the Pacific Northwest, and the FKR-1 only had a range of about 150 km. Both the R-12 and R- 14 could carry thermonuclear warheads, often referred to as Hydrogen bombs, of megaton size, meaning that they contained the explosive power of at least one million tons of TNT. The FKR-1 missiles stationed in Cuba carried 14-kiloton tactical nuclear weapons, which are of a smaller size and useful for more precise battlefield scenarios, with the potential to attack a particular enemy target without the widespread fallout. In particular, they were strategically beneficial in the event of another US invasion because they could target US ships and positions without affecting nearby Cubans.They were a principal reason that the US did not choose to invade during the Cuban Missile Crisis, as President John F. Kennedy said it would be a very bloody fight.