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". [5]
Historic/Defunct: