United States Secretary of Defense

The 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 War was replaced by the Secretary of the Army and, along with the Secretary of the Navy and the new Secretary of the Air Force, became non-Cabinet positions placed 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.

Organization

In the U.S. Armed Forces, the Secretary of Defense is often referred to as SecDef.

The SecDef and the President together constitute the National Command Authority (NCA), which has sole authority to launch strategic nuclear weapons. All nuclear weapons are governed by the two-man rule, even at the highest levels in government. Both individuals must concur before a strategic nuclear strike may be ordered.

The SecDef, as the head of the United States Office of the Secretary of Defense, is assisted by a Deputy Secretary and five 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.

The Secretary of Defense also supervises the six members of the Joint Chiefs of Staff and the commanders of the ten Combatant Commands.

List of Secretaries of Defense

#	Picture	Name	Term of Office		President(s) served under
#	Picture	Name	Start	End	President(s) served under
1	James Forrestal	James Vincent Forrestal	September 17, 1947	March 28, 1949	Harry S. Truman
2	Louis A. Johnson	Louis Arthur Johnson	March 28, 1949	September 19, 1950	Harry S. Truman
3	George C. Marshall	General George Catlett Marshall, Jr.	September 21, 1950	September 12, 1951	Harry S. Truman
4	Robert A. Lovett	Robert Abercrombie Lovett	September 17, 1951	January 20, 1953	Harry S. Truman
5	Charles E. Wilson	Charles Erwin Wilson	January 20, 1953	October 8, 1957	Dwight D. Eisenhower
6	Neil H. McElroy	Neil Hosler McElroy	October 9, 1957	December 1, 1959	Dwight D. Eisenhower
7	Thomas S. Gates	Thomas Sovereign Gates	December 2, 1959	January 20, 1961	Dwight D. Eisenhower
8	Robert McNamara	Robert Strange McNamara	January 21, 1961	February 29, 1968	John F. Kennedy, Lyndon B. Johnson
9	Clark M. Clifford	Clark McAdams Clifford	March 1, 1968	January 20, 1969	Lyndon B. Johnson
10	Melvin R. Laird	Melvin Robert Laird	January 22, 1969	January 29, 1973	Richard Nixon
11	Elliot L. Richardson	Elliot Lee Richardson	January 30, 1973	May 24, 1973	Richard Nixon
12	Schlesinger	James Rodney Schlesinger	July 2, 1973	November 19, 1975	Richard Nixon, Gerald Ford
13	Rumsfeld	Donald Henry Rumsfeld	November 20, 1975	January 20, 1977	Gerald Ford
14	Harold Brown	Harold Brown	January 21, 1977	January 20, 1981	Jimmy Carter
15	Caspar W. Weinberger	Caspar Willard Weinberger	January 21, 1981	November 23, 1987	Ronald Reagan
16	Carlucci	Frank Charles Carlucci III	November 23, 1987	January 20, 1989	Ronald Reagan
17	Cheney	Richard Bruce Cheney	March 21, 1989	January 20, 1993	George H. W. Bush
18	Les Aspin	Leslie Aspin, Jr.	January 21, 1993	February 3, 1994	Bill Clinton
19	William J. Perry	William James Perry	February 3, 1994	January 24, 1997	Bill Clinton
20	William S. Cohen	William Sebastian Cohen	January 24, 1997	January 20, 2001	Bill Clinton
21	Rumsfeld	Donald Henry Rumsfeld	January 20, 2001	December 18, 2006	George W. Bush
22	Gates	Robert Michael Gates	December 18, 2006	Incumbent	George W. Bush

Line of succession

In an Executive Order of December 22, 2005, President George W. Bush modified the line of succession regarding who would act as Secretary of Defense in the event of a vacancy or incapacitation as follows:

Trivia

Despite being second only to the President in regard to military affairs, the position has only once been held by a retired general (George C. Marshall), although many Secretaries of Defense have had previous military service.