At the end of World War 2, the U.S. bombed Japan to prevent the spread of their reign. This opened the door to the weaponization of nuclear power.
The Atomic Bomb was the first nuclear bomb to be used. It was used on Japan at the end of WWII by the U.S.
The Cuban Missile Crisis
Both the U.S.S.R. and the U.S. tested ballistic missiles in the atmosphere to test their distance and their effect on things. Unfortunately, this caused radioactive fallout to occur and for people to get sick because of it.
I.C.B.M.s were ballistic missile assembly and launch sites built to be mobilized quickly if nuclear war broke out. Many I.C.B.M.s were built in Cuba during the Cuban Missile Crisis.
Definitely not a Secret Military Base
This is definitely NOT an I.C.B.M.
During the Cold War, there was a period of time where the U.S.S.R. and the U.S. were close to nuclear warfare. The U.S.S.R. put I.C.B.M.s in Cuba to prepare for war.
The end of the Nuclear Arms Race ended with the Cuban Missile Crisis and the block on a certain amount of nuclear weapons each country is allowed.