Defcon 5

The defense readiness condition (DEFCON) is an alert state used by the United States Armed Forces. The DEFCON system was developed in 1959 by the Joint Chiefs of Staff (JCS) and unified and specified combatant commands. It prescribes five graduated levels of readiness for the U.S. military. It increases in severity from DEFCON 5 to DEFCON 1 to match varying military situations, with DEFCON 1 signaling the impending outbreak of nuclear warfare. For security reasons, the U.S. military does not announce a DEFCON level to the public.