United States Department of Defense

The United States Department of Defense (DoD), also referred to as the Department of War, is an executive department of the United States federal government charged with coordinating and supervising the United States Armed Forces, which are the Army, Navy, Marines, Air Force, Space Force and, for some purposes, the Coast Guard, together with related functions and agencies. It is headquartered at the Pentagon in Arlington County, Virginia, and is led by the secretary of defense, a cabinet-level official who reports directly to the president. Three military departments sit inside it, the Department of the Army, the Department of the Navy and the Department of the Air Force, as do four national intelligence services and agencies such as the Defense Advanced Research Projects Agency, the Missile Defense Agency and the Space Development Agency. The National Security Act of 1947 created the National Military Establishment, which was renamed the Department of Defense on 10 August 1949. As of November 2022 it had over 1.4 million active-duty personnel and over 747,000 civilian employees.