Cuban Missile Crisis: DEFCON 2

DEFCON stands for defense readiness condition. It is a five-stage alert system used by the United States armed forces with 5 being the lowest level and 1 being the highest. During the Cuban Missile Crisis, the US reached its highest level of defense readiness to date: DEFCON 2.

https://www.youtube.com/watch?v=lUMZDtpErcI