defense emergency

An emergency condition that exists when: a. a major attack is made upon US forces overseas or on allied forces in any theater and is confirmed by either the commander of a command established by the Secretary of Defense or higher authority; or b. an overt attack of any type is made upon the United States and is confirmed either by the commander of a command established by the Secretary of Defense or higher authority. defense in depth The siting of mutually supporting defense positions designed to absorb and progressively weaken attack, prevent initial observations of the whole position by the enemy, and to allow the commander to maneuver the reserve.