The defense readiness condition (Defcon) of the U.S. armed forces has reached level 3 amid escalation on the Ukraine-Russia border and ongoing conflict in Ethiopia, among other factors, the Defcon Level Warning System reported on Monday.

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.