DoD

The Department of Defense (DoD) is an executive department of the United States federal government charged with coordinating and supervising national defense and the activities of the armed forces. It is headed by the Secretary of Defense, a civilian who reports to the President, and operates under civilian control of the government. The DoD's headquarters are at the Pentagon, near Washington, D.C.

The DoD was created in 1947 by the National Security Act, combining responsibilities of the former Department of War and Department of the Navy and establishing the United States Space Force in 2019 as a separate service within the Department of the Air Force. The department oversees the Armed Forces and defense-related activities during peacetime and war.

Organization and functions: The department includes three military departments—the Army, the Navy (including the Marine Corps as a component) and the Space Force—along with defense-wide agencies and field activities. The Joint Chiefs of Staff provide military advice to the Secretary and the President. DoD responsibilities include manpower, training, procurement, logistics, research and development, and operations planning. It commands the Unified Combatant Commands that conduct military operations around the world.

The DoD reports to Congress and is subject to annual budgeting and oversight. It maintains internal watchdogs, including an independent Inspector General. The department has periodically restructured to improve joint operations and civilian oversight, most notably after the Goldwater-Nichols Act of 1986. Its stated mission includes deterring war, defending the United States and its interests, and providing security cooperation worldwide.