Overview

The United States Secretary of Defense is the senior civilian official in charge of the Department of Defense (DoD). As a Cabinet member and principal defense policy advisor to the President, the Secretary exercises civilian authority over the armed forces, shapes high-level strategy and budgets, and represents defense interests within the federal government.

Roles and responsibilities

Statutory duties combine policy, management and operational oversight. Key functions include:

  • Formulating and implementing defense policy and national security strategy.
  • Directing the activities of the military departments and establishing priorities for resources and force structure.
  • Overseeing the National Military Command System and supervising intelligence and acquisition programs.
  • Serving on the National Security Council and coordinating with other Cabinet departments.

History and appointment

The office was created by the National Security Act of 1947, which merged separate War and Navy functions into a unified department; James Forrestal served as the first Secretary of Defense. The Secretary is nominated by the President and must be confirmed by the Senate. By law the holder is expected to be a civilian, although Congress can waive the requirement in exceptional cases.

Authority and military relationship

Changes in law, notably the Goldwater-Nichols Act of 1986, clarified command relationships so that operational authority runs from the President to the Secretary of Defense to combatant commanders. The Secretary works closely with the Chairman of the Joint Chiefs of Staff, who is the principal military adviser but does not exercise operational command.

Succession and notable facts

The Secretary of Defense is sixth in the presidential line of succession (presidential succession). The position has been held by civilian leaders with varied backgrounds—former legislators, academics, and business executives—and has often been pivotal during crises, procurement reforms, and major conflicts.

The office combines political accountability with stewardship of one of the world’s largest organizations, balancing military effectiveness, budgetary constraint, and civilian oversight of the armed forces.