Defense Ready Condition (DEFCON) Levels are a way of identifying the current threat level faced by the Department of Defense and the United States military. These levels, on a scale from one to five, indicate the highest level of threat and readiness for it to the lowest level of preparedness required for peacetime. (We’ll cover the individual levels below).

DEFCON levels are not restricted to an indication of the readiness of troops, aircraft, ships, and armor. DEFCON also indicates how severe a nuclear, biological, or chemical threat might be. The most severe DEFCON levels specifically mention nuclear weapons.

Five Levels Of DEFCON 

Defense Ready Conditions, as mentioned above, range from five to one:

Readiness condition	Exercise term	Readiness	Description
DEFCON 1	COCKED PISTOL	Maximum readiness. Immediate response.	Nuclear war is imminent or has already started
DEFCON 2	FAST PACE	Armed forces ready to deploy and engage in less than six hours	Next step to nuclear war
DEFCON 3	ROUND HOUSE	Air Force ready to mobilize in 15 minutes	Increase in force readiness above that required for normal readiness
DEFCON 4	DOUBLE TAKE	Above normal readiness	Increased intelligence watch and strengthened security measures
DEFCON 5	FADE OUT	Normal readiness	Lowest state of readiness

Defense department plans from the late 20th century include “EMERGCONs” which are a similar type of hierarchical threat level identification system related to the nation’s response to a missile attack or an attempted attack. These can include the following:

Defense Emergency: A major military effort against U.S. forces or allies in overseas locations.

Air Defense Emergency: An attack on the United States, Canada, or military installations in Greenland “by hostile aircraft or missiles”. 

DEFCON Is An American System

DEFCON levels are a tool for the Defense Department and the federal government; they have not been instituted as a global standard such as Greenwich Mean Time or the Geneva Conventions. DEFCON threat levels change in unique ways–some parts of the military may operate at a higher DEFCON level than the rest of the uniformed services as a whole. DEFCONs may be increased at a military base only, or a theatre-level command, or in other ways as the government sees fit.

When Have Higher DEFCON Levels Occurred?

DEFCON levels are not a world-wide, globally accepted type of threat warning system. These levels are used by the United States military and not all DEFCON level changes affect or require the use of the entire military or DoD. Some changes to DEFCON levels may be appropriate for a specific unit, base, or mission while the rest of the DoD remains at a different level. 

Some sources report the United States has never entered anything higher than DEFCON 3, but this is technically untrue. DEFCON 2 was announced in 1962 during the Cuban Missile Crisis, and was announced briefly in 1991 at the start of the first Gulf War. But for both purposes, the ENTIRE U.S. military was NOT put on DEFCON 2.

DEFCON Is Unrelated To…

The DEFCON levels should not be confused with a later system instituted after the 9/11 attacks. The United States Department of Homeland Security Advisory System, introduced by the Bush administration in 2002, relies on a color-coded system rather than numbers:

• Red: Severe threat or risk
• Orange: High risk or threat
• Yellow: An elevated, significant risk
• Blue: A ‘Guarded” or general risk
• Green: Low risk 

In 2011, the Department of Homeland Security ended the use of this color-coded alert system. It was replaced with the “National Terrorism Advisory System (NTAS)”. Threat information under this system is issued with published advisories and alerts.

Defense Conditions are also not the same as the following threat warnings employed by the Department of Defense. These threat warnings have no connection at all with DEFCON levels:

Force Protection Conditions (FPCONS)

Used at individual military bases as a local threat evaluation. Threat environments and readiness expectations are indicated by FPCON levels starting at “Normal”, and include:

• Alpha
• Bravo
• Charlie
• Delta

Alpha and Bravo indicate potential threats. Charlie and Delta indicate an elevated likelihood of a terrorist attack, with Delta indicating the presence of military intelligence or other indicators that an attack may happen.

Information Operations Condition (INFOCON)

DoD computer networks have their own threat level indications. INFOCON was created in 1999 and its levels are based on the level of readiness required rather than the level of threat perceived.

Watch Conditions (WATCHCONS) are a theatre-unique system for protection of DoD and overseas partners in defense of South Korea.

• WATCHCON 4: “Normal peacetime”
• WATCHCON 3 “Important threat”
• WATCHCON 2 “Vital threat”
• WATCHCON 1 “Wartime”