The defense readiness condition is an alert state used by the United States Armed Forces.
The DEFCON system was developed by the Joint Chiefs of Staff and unified and specified
combatant commands. It prescribes five graduated levels of readiness for the U.S. military,
and increase in severity from DEFCON 5 to DEFCON 1 to match varying military situations.
DEFCONs are a subsystem of a series of Alert Conditions, or LERTCONs, that also includes
Emergency Conditions. There is no single DEFCON status for the country, and in fact different
branches of the military can be at different levels of DEFCON at the same time. DEFCONs
should not be confused with similar systems used by the U.S. military, such as Force Protection
Conditions, Readiness Conditions, Information Operations Condition and its future replacement
Cyber Operations Condition, and Watch Conditions, or the former Homeland Security Advisory System
used by the United States Department of Homeland Security.
Levels DEFCONs vary between many commands and have
changed over time, and the United States Department of Defense uses exercise terms when referring
to the DEFCONs. This is to preclude the possibility of confusing exercise commands with actual
operational commands. On 12 January 1960, NORAD "proposed the adoption of the readiness
conditions of the JCS system", and information about the levels was declassified in 2006:
Movies and popular culture often misuse the DEFCON system by "going to DEFCON 5" when
a nuclear war is imminent. In fact, DEFCON 5 is the lowest state of readiness. The highest
state, DEFCON 1, has never been called for. History
After NORAD was created, the command used different readiness levels subdivided into
eight conditions, e.g., the "Maximum Readiness" level had two conditions "Air Defense Readiness"
and "Air Defense Emergency". In October 1959, the JCS Chairman informed NORAD "that Canada
and the U. S. had signed an agreement on in­creasing the operational readiness of NORAD forces
during periods of international tension." After the agreement became effective on 2
October 1959, the JCS defined a system with DEFCONs in November 1959 for the military
commands. The initial DEFCON system had "Alpha" and "Bravo" conditions and Charlie/Delta under
DEFCON4, plus an "Emergency" level higher than DEFCON1 with two conditions: "Defense
Emergency" and the highest, "Air Defense Emergency". DEFCON 2
Cuban Missile Crisis The highest confirmed DEFCON ever was Level
2. During the Cuban Missile Crisis on October 22, 1962, the U.S. Armed Forces were ordered
to DEFCON 3. On October 26, Strategic Air Command was ordered to DEFCON 2, while the
rest of the U.S. Armed Forces remained at DEFCON 3. SAC remained at DEFCON 2 until November
15. DEFCON 3
Yom Kippur War On October 6, 1973, Egypt and Syria launched
a joint surprise attack on Israel resulting in the Yom Kippur War. The U.S. became concerned
that the Soviet Union might intervene and on October 25, U.S. forces including Strategic
Air Command, Continental Air Defense Command, European Command and the Sixth Fleet were
placed on DEFCON 3. Over the following days, the various forces reverted to normal status
with the Sixth Fleet standing down on November 17.
September 11 attacks The third time the United States reached DEFCON
3 was during the September 11 attacks of 2001. U.S. Secretary of Defense Donald Rumsfeld
ordered the increased DEFCON level, and also a stand-by for a possible increase to DEFCON
2, which did not occur. Operations
The DEFCON level is controlled primarily by the U.S. President and the U.S. Secretary
of Defense through the Chairman of the Joint Chiefs of Staff and the Combatant Commanders,
and each DEFCON level defines specific security, activation and response scenarios for the
troops in question. Different branches of the U.S. Armed Forces
and different bases or command groups can be activated at different defense conditions.
There is no single DEFCON status for the country, as they are decided on an individual basis
by respective branches of the military. In other media
DEFCON was used significantly in the films WarGames, Thirteen Days, Watchmen, Independence
Day, The Sum of All Fears, Crimson Tide and Olympus Has Fallen.
The real-time strategy game DEFCON simulates the outbreak of thermonuclear war, and advances
through the DEFCON levels as each match progresses. See also
Doomsday Clock HURCON — Hurricane Condition threat rating.
National Command Authority National Military Command Center
UK Threat Levels — British equivalent to American DEFCON
References
External links Media related to DEFCON at Wikimedia Commons