Cuban Missile Crisis- Global Conflict.

http://www.csmonitor.com/Commentary/Opinion/2012/1015/50-years-after-Cuban-missile-crisis-closer-than-you-thought-to-World-War-III

Why was the Cuban Missile Crisis a global conflict?
The U.S never knew what a problem nuclear weapons were. They were being developed all over the world but no one had been threatened with them. The President and his advisors realized that something had to be done in order to protect themselves and the U.S citizens.

 I can't imagine how scary it must have been to fear something that you don't quite understand yet.