In United States military doctrine, an alert condition (LERTCON) is a measure of the level of action and readiness to be taken in a given situation.
LERTCON is used by US and Allied forces who are assigned to NATO. There are specific procedures laid out for responses to changes in LERTCON. LERTCON levels can be broken down into high-alert emergency condition levels (EMERGCONs) and the more common Defence Condition levels (DEFCONs).
- LERTCON 5/4: Peacetime conditions.
- LERTCON 3.5: Military vigilance.
- LERTCON 3: Simple alert.
- LERTCON 2: Reinforced alert.
- LERTCON 1: General alert.
Should not be confused with similar systems used by the US military, such as:
- Alert Condition (LERTCON).
- Emergency Condition (EMERGCON).
- Defence Readiness Condition (DEFCON).
- Force Protection Condition (FPCON), previously THREATCON.
- Readiness Condition (REDCON).
- Information Operations Condition (INFOCON), and its future replacement Cyber Operations Condition (CYBERCON).
- Watch Condition (WATCHCON), or the former Homeland Security Advisory System used by the United States Department of Homeland Security.
- Hurricane Condition (HURCON), a military developed scale.