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Defense Condition

For the technology conference/hacker convention, see DEF CON.

Defense Condition is a measure of the activation and readiness level of the United States armed forces. DEF CON is the acronym of "DEFense CONdition". These defense conditions describe progressive postures for use between the Joint Chiefs of Staff and the commanders of unified commands. DEFCONs are matched to the situations of military severity.

In a national emergency, seven different alert conditions (refered to as LERTCONs) can be issued. The seven LERTCONs are broken down into 5 Defense Conditions (refered to as DEFCONs) and two Emergency Conditions (refered to as EMERGCONs).

Table of contents
1 Descriptions of DEFCONs
2 Conditions
3 See Also
4 External links, resources, and references

Descriptions of DEFCONs

DEFCONs are phased increases in combat readiness. Expanded explanations follow below.

DEFCON 5 : Peacetime.
DEFCON 4 : Peacetime; Increased intelligence; Strengthened security measures.
DEFCON 3 : Increased force readiness.
DEFCON 2 : Increased force readiness (less than maximum).
DEFCON 1 : Maximum force readiness.

DEFCON 5 is the condition used to designate normal peacetime military readiness. An upgrade in military preparedness is typically made by the Joint Chiefs of Staff and announced by the United States Secretary of Defense. The level can be increased, respectively, to DEFCON 4, 3, 2, and 1.

DEFCON 4 refers to normal, increased intelligence and the heightening of national security measures. Readiness remained at this level throughout most of the Cold War.

DEFCON 3 refers to an increase in force readiness above normal. United States military commands (minus the Strategic Air Command, at heightened alert on DEFCON 2) went to this level in 1962 during the Cuban Missile Crisis. All United States forces went on DEFCON 3 during the 1973 Yom Kippur War due to fears of Soviet military intervention in the Middle East.

DEFCON 2 refers to a further increase in force readiness just below maximum readiness. It has only been declared once; see above.

DEFCON 1 refers to maximum readiness. This has never been used but is reserved for imminent or ongoing attack on US military forces or US territory by a foreign military power.


Different branches of the armed forces (e.g. army, navy, air force) and different bases or command groups can be activated at different defense conditions. For much of the Cold War US ICBM sites were always at DEFCON 4 rather than 5.

The highest alert condition the US military has been at was DEFCON 2. During the Cuban missile crisis SAC was ordered to 2 and the rest of the US military to 3 on October 22, 1962. SAC remained at 2 until November 15. Higher alert conditions were also ordered during the Yom Kippur War (1973).

The DEFCON level is controlled primarily by the President and the Joint Chiefs of Staff, and each DEFCON level defines specific security, activation and response scenarios for the troops in questions.

See Also

External links, resources, and references