Washington: The defense readiness condition (Defcon) of the US armed forces has reached level 3 as Russia continues to amass troops on the Ukrainian border, among other factors, the Defcon Level Warning System, a private organization monitoring military readiness and terrorist and nuclear threats to the United States, reported on Monday.
There are five Defcon alert levels, where number one is the highest, which means a state of war or nuclear threat.
Defcon 3 was reached during the 1991 Gulf War, partially during the 1962 Cuban missile crisis, and most recently after the 9/11 attacks in 2001.