II.

Purpose

The department directs and controls the armed forces and assists the president in the direction of the nation's security.

By authority of the National Security Act of 1947, the National Military Establishment was created on September 18, 1947. The first secretary was primarily a coordinator, developing general policies for the three executive departments—the Department of the Navy, Department of the Army, and newly created Department of the Air Force. The act was amended in 1949, renaming the National Military Establishment the Department of Defense. The former War Department became part of the Department of the Army. A chairman of the Joint Chiefs of Staff was added, and the military departments were placed under the Defense Department without Cabinet status. Major legislation in 1953, 1958, 1977, 1986, and 2002 resulted in increased responsibilities for the secretary, establishment of an operational chain of command to the unified and specified commands, and authority (for the secretary) to bypass the military departments on operational matters.