United States Secretary of Defense to die was Frank Carlucci (1987–1989), on 3 June 2018. United States Secretary of Defense The Secretary of Defense (SecDef) is the leader and chief executive officer of the United States Department of Defense, the executive department of the Armed Forces of the United States. The Secretary of Defense's position of command and authority over the United States' military is second only to that of the President and Congress, respectively. This position corresponds to what is generally known as a Defense Minister in many other countries. The Secretary of Defense is appointed by the President with the advice and consent
United States Secretary of Defense Department of Defense, "the principal assistant to the President in all matters relating to Department of Defense", and has "authority, direction and control over the Department of Defense". Because the Constitution vests all military authority in Congress and the President, the statutory authority of the Secretary of Defense is derived from their constitutional authorities. Since it is impractical for either Congress or the President to participate in every piece of Department of Defense affairs, the Secretary of Defense, and the Secretary's subordinate officials generally exercise military authority. As the head of DoD, all officials, employees and service members are "under"