An alert state or state of alert is an indication of the state of readiness of the armed forces for military action or a state against natural disasters, terrorism or military attack. The term frequently used is "on high alert".[1] Examples scales indicating alert state are the DEFCON levels of the US military,[2] South Korea's "Jindogae" system,[3] and the UK Threat Levels.[4] High alert states are synonymous with "red alert".
Historic/Defunct: