How To Understand The DEFCON Scale: 9 Steps (with Pictures)

In the U.S., the DEFCON scale is used to measure how alert the country’s defense forces are in response to a potential national emergency. DEFCON is short for Defense Ready Condition. To understand the DEFCON scale, start by getting to know the levels. There are 5 DEFCON levels, with 5 being the least severe and 1 being the most severe. DEFCON level 5 is defined as normal peacetime readiness. This level is used when the country is not at war and there are no major potential threats to national security. DEFCON 4 is a slightly elevated level of readiness, characterized by an increase in intelligence gathering and heightened security measures. The U.S. armed forces might go to DEFCON 4 in response to potential terrorist activity or military threats, but it doesn’t necessarily mean that there’s immediate danger of an attack. Level 3 is used during tense political or military situations where it might be necessary to mobilize the country’s armed forces at any moment—for instance, if there’s a chance that the U.S. or one of its allies is under threat of military action. At DEFCON 3, the Air Force is always ready to mobilize within just 15 minutes of notice. DEFCON 2 is used for severe situations, such as when there’s a major terrorist attack or immediate danger of a major military action against the United States or its allies. At DEFCON 2, all of the country’s combat forces are set to deploy within about 6 hours of notice. DEFCON 1 is the most severe level, which is used for extreme situations, such as an outbreak of nuclear war. When the U.S. military is at DEFCON 1, all armed forces are supposed to be ready for immediate action at all times. Since DEFCON information is classified, it’s not clear whether the U.S. has ever reached DEFCON 1 status. The DEFCON scale is used in combination with other emergency readiness scales, such as LERTCON, REDCON, and EMERGCON. Keep in mind that while there’s some general information about the DEFCON scale available to the general public, the details of how DEFCON levels are decided—and what actions the country’s armed forces take in reaction to each level—are classified. For examples of each of these DEFCON levels, keep reading! Did this summary help you?YesNo