The DEFCON (Defense Readiness Condition) rating used in the United States is a measure of the readiness of national defense forces. The lowest level in DEFCON is level 5 (for peaceful conditions), while the highest level is level 1 (for threatening global situations, such as nuclear war). Understanding DEFCON levels is important for personal enrichment as well as to avoid improper use (e.g., “We are now at DEFCON six.”)
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Part 1 of 3: DEFCON. Ranking Table
| DEFCON levels | Alert Level | Examples in the Past |
|---|---|---|
| 5 | Normal preparedness in peacetime | The most basic standards used in peacetime |
| 4 | Enhanced intelligence and security measures | Sporadically during the Cold War, in the fight against terrorism |
| 3 | The readiness of the armed forces is above normal levels; Air Force ready to move in 15 minutes | Post-attacks 8/11 (2001), Yom Kippur War (1973), Operation Paul Bunyan (1976), after the Four Nations Treaty (1960) |
| 2 | High alertness; all armed forces ready to move within 6 hours | Cuban Missile Crisis (1962) |
| 1 | Maximum alertness; all armed forces are ready to fight; Nuclear war may or may not be avoided | There is not any |
Part 2 of 3: Understanding DEFCON Levels
Step 1. Learn how to read DEFCON levels
The DEFCON rating is a way of assigning a numerical value to describe the state of American military readiness. A higher DEFCON value is used to describe a lower state of alertness (in more peaceful and calm situations), while a lower DEFCON value is used to describe a high state of alertness (in more tense situations when military action may be required). DEFCON level 5 describes normal peaceful conditions, while DEFCON level 1 (which has never been used) describes the most dangerous conditions, such as thermonuclear war.
Note that different branches of the armed forces may be in different DEFCON levels. For example, in the Cuban Missile Crisis, which was one of the most tense situations in American military history, Strategic Air Command troops used DEFCON 2, while other military forces used DEFCON 3
Step 2. Use DEFCON 5 for peaceful conditions
DEFCON level 5 is a good thing-it's a condition that describes normal military preparedness in times of no threat. At DEFCON 5, the American military did not implement more security and precautionary measures than would normally be necessary.
Remember that DEFCON 5 does not mean that the world is at peace. Conflicts, even major ones, can still be happening in the world when DEFCON 5 is implemented. In this case, however, the American military considers these conflicts not to pose an important defense threat
Step 3. Use DEFCON 4 for higher alertness
DEFCON 4 is the first alert level above the base DEFCON 5 level, and as such represents a less drastic increase in alertness (though the upgrade from DEFCON 5 to DEFCON 4 is certainly an important move). This DEFCON level represents increased intelligence efforts, and, sometimes, increased national defense measures. However, this does not necessarily indicate that a military force (or state) is in imminent threat of attack or danger.
In the modern world, DEFCON 4 is usually considered appropriate to apply after a mild to moderate terrorist attack, after politically motivated assassinations, or after serious criminal plots have been uncovered. This may be done in anticipation of further attacks or violence as a measure to prepare for or prevent them
Step 4. Use DEFCON 3 for tense military or political situations
A situation that requires DEFCON 3 is a serious one. While not necessarily a direct threat to America's stability, this situation requires high vigilance. At this level, American military forces are on high alert for mobilization. Most notably, the air force was ready to move in just 15 minutes. In addition, all military communications can also be encrypted based on secret protocols.
Historically, DEFCON 3 is usually used when there is a possibility of military action against America or one of its allies. For example, in Operation Paul Bunyan, which later led to the implementation of DEFCON 3, two American soldiers were killed by North Korean forces in the Korean Demilitarized Zone. In this case, DEFCON 3 was applied because there was a possibility that any wrongdoing in the conflict it caused could lead to open war on the Korean border (which is an area of high political and military tension, past and present)
Step 5. Use DEFCON 2 for major threats
DEFCON 2 represents a further increase in military preparedness, only a notch below maximum alertness. Combat troops were prepared for major operations in just a few hours. Upgrading to DEFCON 2 level is a very serious act. The situations that trigger DEFCON 2 are considered to carry the risk of dangerous military operations against the United States or its allies, including the use of nuclear weapons. DEFCON 2 is usually only used for the most critical international military situations.
The most important example of DEFCON 2 ever being implemented was during the Cuban Missile Crisis, although DEFCON 2 was only applied to Strategic Air Command. This situation is considered to be the only situation that requires the implementation of DEFCON 2, but since information related to the DEFCON level is usually kept confidential, there may also be other situations that require the implementation of DEFCON 2
Step 6. Use DEFCON 1 for maximum alert level
DEFCON 1 represents maximum military preparedness; troops with DEFCON 1 status are prepared to move immediately around the clock. DEFCON 1 is only used for the truly most dangerous situations, such as a nuclear war involving the United States or its allies.
- Although DEFCON grades are usually kept secret until the situation is resolved, as noted above, it is generally considered that DEFCON 1 was never used for any branch of the American armed forces.
- Some limited and unverifiable evidence suggests that DEFCON 1 may have been used for certain military units during the first Gulf War. Even if the evidence is correct, this status is only used for certain units and not for the military force as a whole.
Part 3 of 3: Learning More about DEFCON
Step 1. Understand how DEFCON levels are applied
The detailed process of how the military declares an increase in DEFCON levels is not fully known to the public. It is generally assumed that increased military readiness is ordered by the Joint Chiefs of Staff, with the approval of the president. However, some stories suggest that the top military leaders could raise DEFCON levels without the president's involvement; for example, some sources report that the Strategic Air Command's decision to apply DEFCON 2 to the Cuban Missile Crisis occurred without President Kennedy's input.
Keep in mind again that the exact actions taken by military forces in each level of DEFCON are kept secret, for obvious reasons. As such, most of the publicly available information about DEFCON tiers is based solely on old documents that are no longer classified, or historic drastic DEFCON upgrades that were later made public after the situation was over. While some non-military and non-governmental sources may claim to know the current status of DEFCON, this claim cannot be verified
Step 2. Also be aware of other United States alert levels
The DEFCON rating is not the only measure that governments and the military use to gauge their preparedness for internal and external hazards. Other levels of alertness include LERTCON (used by the United States and its NATO allies), REDCON (used by individual US military units), and others. However, the most important alert level besides DEFCON is probably the EMERGCON level. This condition (which was never used before) was applied during nuclear war and included instructions for civilians in addition to military instructions. EMERGCON has two levels, which are:
- Defense Emergency: Performed when there is a threat of a malicious attack against the US or its allies abroad. Issued by unit commander or higher authority.
- Air Defense Emergency: Used in the event of an attack on US, Canadian, or military installations in Greenland. Issued by the Commander-in-Chief of the North American Space Defense Command.
- When EMERGON is applied, all military forces automatically use DEFCON 1.
Step 3. Do some research on the history of DEFCON tiers
While most information about the history of DEFCON tiers is of course kept secret, the information that is no longer classified and is open to the public is equally interesting. Initiated in the late 1950s as a way for NORAD to coordinate military movements between the US and Canada, the DEFCON system has undergone several changes to the system in use today.
