This position was created in 1947 when the Navy, Army, and newly created Air Force were merged into the new National Military Establishment. In the same massive reorganization, the Secretary of the Navy was changed to a non-Cabinet position placed under the Secretary of Defense and the Secretary of War was replaced by the Secretary of the Army, also a non-Cabinet position under the Secretary of Defense. In 1949, the National Military Establishment was renamed the Department of Defense, which remains the current name of the department.
He is assisted by a Deputy Secretary and 5 Under Secretaries in the fields of Acquisition, Technology & Logistics; Comptroller/Chief Financial Officer; Intelligence; Personnel & Readiness; and arguably the most important, Policy. All of these positions require Senate confirmation.
See http://www.defenselink.mil/osd/topleaders.html for information on each position and biographies of the current Deputy Secretary (DepSecDef) and Under Secretaries (USDs).
The Office of the Secretary of Defense Identification Badge is a U.S. military badge of the Department of Defense issued to members of the U.S. military who are permanently assigned as military aides to the Secretary of Defense in the Department of Defense.
Personnel who are awarded the Secretary of Defense Identification Badge include military aides to the Secretary of Defense, senior flag and general officers assigned to The Pentagon, as well as the service chiefs and the Chairman of the Joint Chiefs of Staff.
The Office of the Secretary of Defense Identification Badge was first created in 1949 and was referred to as the "National Military Establishment Identification Badge." In 1950, the badge was renamed as "Department of Defense Identification Badge" and adopted its current name on December 20, 1962.
The director of the DIA is the main adviser to the Secretary of Defense and the Chairman of the Joint Chiefs of Staff on matters related to military intelligence.
Acting on the recommendations of the Joint Study Group, Secretary of Defense Robert S. McNamara advised the Joint Chiefs of Staff (JCS) of his decision to establish the Defense Intelligence Agency in February 1961.
It was a union of Defense intelligence and counterintelligence activities, and did not add administrative layering within the Defense intelligence community.