The United States secretary of defense (SecDef), secondarily titled the secretary of war (SecWar), is the head of the United States Department of Defense (DoD), the executive department of the U.S. Armed Forces, and is a high-ranking member of the cabinet of the United States. The secretary of defense's position of command and authority over the military is second only to that of the president of the United States, who is the commander-in-chief. This position corresponds to what is generally known as a defense minister in many other countries. The president appoints the secretary of defense with the advice and consent of the Senate, and is by custom a member of the Cabinet and by law a member of the National Security Council.

Subject only to the orders of the president, the secretary of defense is in the chain of command and exercises command and control, for both operational and administrative purposes, over all DoD-administered service branches – the Army, Marine Corps, Navy, Air Force, and Space Force – as well as the Coast Guard when its command and control is transferred to the Department of Defense. Only the secretary of defense (or the president or Congress) can authorize the transfer of operational control of forces between the three military departments (Department of the Army, the Navy, and the Air Force) and the eleven Unified Combatant Commands.

To ensure civilian control of the military, U.S. law provides that the secretary of defense cannot have served as an active-duty commissioned officer in the military in the preceding seven years except for generals and admirals, who cannot have served on active duty within the previous ten years. Congress can legislatively waive this restriction and has done so three times, for George C. Marshall Jr., James N. Mattis, and Lloyd J. Austin III. The chairman of the Joint Chiefs of Staff is the principal military adviser to the secretary of defense and the president; while the chairman may assist the secretary and president in their command functions, the chairman is not in the chain of command.

Because the secretary of defense is vested with legal powers that exceed those of any commissioned officer, and is second only to the president in the military hierarchy, its incumbent has sometimes unofficially been referred to as "deputy commander-in-chief". The secretary of state, the secretary of the treasury, the secretary of defense, and the attorney general are generally regarded as the four most important (and are officially the four most senior and oldest) cabinet officials because of the size and importance of their respective departments.

The current secretary of defense is Pete Hegseth, who was nominated by President Donald Trump and was confirmed by the Senate on 25 January 2025.

History

Seal of the National Military Establishment (1947–1949)

An Army, Navy, and Marine Corps were established in 1775, in concurrence with the American Revolution. The War Department, headed by the secretary of war, was created by Act of Congress in 1789 and was responsible for both the Army and Navy until the founding of a separate Department of the Navy in 1798.

Donald Rumsfeld is sworn in as Secretary of Defense by Associate Supreme Court Justice Potter Stewart as U.S. President Gerald R. Ford and Chairman of The Joint Chiefs of Staff General George S. Brown watch at The Pentagon on 20 November 1975.

Based on the experiences of World War II, proposals were soon made on how to more effectively manage the large combined military establishment. The Army generally favored centralization while the Navy had institutional preferences for decentralization and the status quo. The resulting National Security Act of 1947 was largely a compromise between these divergent viewpoints. It renamed the Department of War the Department of the Army, and added both it and the Department of the Navy to a newly established National Military Establishment (NME). The act also separated the Army Air Forces from the Army to become its own branch of service, the United States Air Force.

A new title was coined by the act for the head of the NME: Secretary of Defense. At first, each of the service secretaries maintained cabinet status. The first secretary of defense, James Forrestal, who in his previous capacity as the secretary of the Navy had opposed the creation of the new position, found it difficult to exercise authority over the other branches with the limited powers his office had at the time. To address this and other problems, the National Security Act was amended in 1949 to further consolidate the national defense structure in order to reduce interservice rivalry, directly subordinate the secretaries of the Army, the Navy and the Air Force to the secretary of defense in the chain of command, and rename the National Military Establishment as the Department of Defense, making it one Executive Department. The position of the deputy secretary of defense, the number two position in the department, was also created at this time.

The general trend since 1949 has been to further centralize management in the Department of Defense, elevating the status and authorities of civilian OSD appointees and defense-wide organizations at the expense of the military departments and the services within them. The last major revision of the statutory framework concerning the position was done in the Goldwater–Nichols Department of Defense Reorganization Act of 1986. In particular, it elevated the status of joint service for commissioned officers, making it in practice a requirement before appointments to general officer and flag officer grades could be made.

As the secretary of defense is a civilian position intended to be independent of the active-duty leadership, a secretary is required to have been retired from service for at least seven (originally ten) years unless a waiver is approved by Congress. Since the creation of the position in 1947, such a waiver has been approved only three times, for Army general George Marshall in 1950, Marine Corps General Jim Mattis in 2017, and retired Army general Lloyd Austin in 2021.

Powers and functions

Department of Defense organizational chart (December 2013)

The secretary of defense, appointed by the president with the advice and consent of the Senate, is by federal law (10 U.S.C. ) the head of the Department of Defense, "the principal assistant to the President in all matters relating to Department of Defense", and has "authority, direction and control over the Department of Defense". Because the Constitution vests all military authority in Congress and the president, the statutory authority of the secretary of defense is derived from their constitutional authorities. Since it is impractical for either Congress or the president to participate in every piece of Department of Defense affairs, the secretary of defense and the secretary's subordinate officials generally exercise military authority.

As the head of DoD, all officials, employees and service members are "under" the secretary of defense. Some of those high-ranking officials, civil and military (outside of OSD and the Joint Staff) are: the secretary of the Army, secretary of the Navy, and secretary of the Air Force, Army chief of staff, commandant of the Marine Corps, chief of naval operations, Air Force chief of staff, chief of space operations, and chief of the National Guard Bureau and the combatant commanders of the Combatant Commands. All these high-ranking positions, civil and military, require Senate confirmation.

The Department of Defense is composed of the Office of the Secretary of Defense (OSD), the Joint Chiefs of Staff (JCS) and the Joint Staff (JS), Office of the Inspector General (DODIG), the Combatant Commands, the Military Departments (Department of the Army (DA), Department of the Navy (DON) & Department of the Air Force (DAF)), the Defense Agencies and DoD Field Activities, the National Guard Bureau (NGB), and such other offices, agencies, activities, organizations, and commands established or designated by law, or by the president or by the secretary of defense.

Department of Defense Directive 5100.01 describes the organizational relationships within the department and is the foundational issuance for delineating the major functions of the department. The latest version, signed by former secretary of defense Robert Gates in December 2010, is the first major re-write since 1987.

Office of the Secretary of Defense

The secretary's principally civilian staff element is called the Office of the Secretary of Defense (OSD) and is composed of the deputy secretary of defense (DEPSECDEF) and six under secretaries of defense in the fields of acquisition & sustainment, research & engineering, comptroller/chief financial officer, intelligence, personnel & readiness, and policy; several assistant secretaries of defense; other directors and the staffs under them. The Secretary of Defense is issuing through the Office of the Secretary of Defense the National Defense Strategy, a major policy document.

The name of the principally military staff organization, organized under the chairman of the Joint Chiefs of Staff, is the Joint Staff (JS).

Awards and decorations

The Defense Distinguished Service Medal (DDSM), the Defense Superior Service Medal (DSSM), the Defense Meritorious Service Medal (DMSM), the Joint Service Commendation Medal (JSCM) and the Joint Service Achievement Medal (JSAM) are awarded, to military personnel for service in joint duty assignments, in the name of the secretary of defense. In addition, there is the Joint Meritorious Unit Award (JMUA), which is the only ribbon (as in non-medal) and unit award issued to joint DoD activities, also issued in the name of the secretary of defense.

The DDSM is analogous to the distinguished services medals issued by the military departments (i.e. Army Distinguished Service Medal, Navy Distinguished Service Medal & Air Force Distinguished Service Medal), the DSSM corresponds to the Legion of Merit, the DMSM to the Meritorious Service Medal, the JSCM to the service commendation medals, and the JSAM to the achievement medals issued by the services. While the approval authority for DSSM, DMSM, JSCM, JSAM and JMUA is delegated to inferior DoD officials: the DDSM can be awarded only by the secretary of defense.

Recommendations for the Medal of Honor (MOH), formally endorsed in writing by the secretary of the military department concerned and the chairman of the Joint Chiefs of Staff, are processed through the under secretary of defense for personnel and readiness, and such recommendations be must approved by the secretary of defense before it can be handed over to the president, who is the final approval authority for the MOH, although it is awarded in the name of Congress.

The secretary of defense, with the concurrence of the secretary of state, is the approval authority for the acceptance and wear of NATO medals issued by the secretary general of NATO and offered to the U.S. permanent representative to NATO in recognition of U.S. servicemembers who meet the eligibility criteria specified by NATO.

Congressional committees

As the head of the department, the secretary of defense is the chief witness for the congressional committees with oversight responsibilities over the Department of Defense. The most important committees, with respect to the entire department, are the two authorizing committees, the Senate Armed Services Committee (SASC) and the House Armed Services Committee (HASC), and the two appropriations committees, the Senate Appropriations Committee and the House Appropriations Committee.

For the DoD intelligence programs the Senate Select Committee on Intelligence and the House Permanent Select Committee on Intelligence have the principal oversight role.

National Security Council

The secretary of defense is a statutory member of the National Security Council. As one of the principals, the secretary along with the vice president, secretary of state and the assistant to the president for national security affairs participates in biweekly Principals Committee (PC) meetings, preparing and coordinating issues before they are brought before full NSC sessions chaired by the president.

Role in the military justice system

The secretary is one of only five or six civilians authorized to act as convening authority in the military justice system for General Courts-Martial (10 U.S.C. : article 22, UCMJ), Special Courts-Martial (10 U.S.C. : article 23, UCMJ), and Summary Courts-Martial (10 U.S.C. : article 24 UCMJ). The others are the president, secretary of the Army, secretary of the Navy, secretary of the Air Force, and secretary of homeland security (when the United States Coast Guard is under the United States Department of Homeland Security and has not been transferred to the Department of the Navy under the Department of Defense).

Salary

The secretary of defense is a Level I position in the Executive Schedule, thus earning a salary of US$246,400, as of October 2024.

List of secretaries of defense

The longest-serving secretary of defense is Robert McNamara, who served for a total of 7years, 39 days. Combining his two non-sequential services as the secretary of defense, the second-longest serving is Donald Rumsfeld, who served just ten days fewer than McNamara. The second-longest unbroken tenure was Caspar Weinberger's, at 6years, 306 days.

The shortest-serving secretary of defense is Elliot Richardson, who served 114 days and then was appointed U.S. attorney general amid the resignations of the Watergate Scandal (this is not counting deputy secretaries of defense William P. Clements and William Howard Taft IV, who each served a few weeks as temporary/acting secretary of defense).

For precursors to this position before the establishment of the Department of Defense, see the lists of secretaries of the Navy and secretaries of war before 1947.

Parties

Democratic Republican Independent / Unknown

Status

No.ImageNameStartEndDurationPartyHome StatePresident(s)
1James Forrestal17 September 194728 March 19491 year, 192 daysDemocraticNew YorkHarry S. Truman (1945–1953)
2Louis A. Johnson28 March 194919 September 19501 year, 175 daysDemocraticWest Virginia
3George C. Marshall21 September 195012 September 1951356 daysIndependentPennsylvania
4Robert A. Lovett17 September 195120 January 19531 year, 125 daysRepublican (cross party)New York
5Charles Erwin Wilson28 January 19538 October 19574 years, 253 daysRepublicanMichiganDwight D. Eisenhower (1953–1961)
6Neil H. McElroy9 October 19571 December 19592 years, 53 daysRepublicanOhio
7Thomas S. Gates Jr.2 December 195920 January 19611 year, 49 daysRepublicanPennsylvania
8Robert McNamara21 January 196129 February 19687 years, 39 daysRepublican (cross party)MichiganJohn F. Kennedy (1961–1963)
Lyndon B. Johnson (1963–1969)
9Clark Clifford1 March 196820 January 1969325 daysDemocraticMarylandLyndon B. Johnson (1963–1969)
10Melvin Laird22 January 196929 January 19734 years, 7 daysRepublicanWisconsinRichard Nixon (1969–1974)
11Elliot Richardson30 January 197324 May 1973114 daysRepublicanMassachusetts
Bill Clements Acting24 May 19732 July 197339 daysRepublicanTexas
12James R. Schlesinger2 July 197319 November 19752 years, 140 daysRepublicanVirginiaRichard Nixon (1969–1974)
Gerald Ford (1974–1977)
13Donald Rumsfeld20 November 197520 January 19771 year, 61 daysRepublicanIllinoisGerald Ford (1974–1977)
14Harold Brown20 January 197720 January 19814 years, 0 daysDemocraticCaliforniaJimmy Carter (1977–1981)
15Caspar Weinberger21 January 198123 November 19876 years, 306 daysRepublicanCaliforniaRonald Reagan (1981–1989)
16Frank Carlucci23 November 198720 January 19891 year, 58 daysRepublicanVirginia
William Howard Taft IV Acting20 January 198921 March 198960 daysRepublicanOhioGeorge H. W. Bush (1989–1993)
17Dick Cheney21 March 198920 January 19933 years, 305 daysRepublicanWyoming
18Les Aspin20 January 19933 February 19941 year, 14 daysDemocraticWisconsinBill Clinton (1993–2001)
19William Perry3 February 199424 January 19972 years, 356 daysDemocraticPennsylvania
20William Cohen24 January 199720 January 20013 years, 362 daysRepublican (cross party)Maine
21Donald Rumsfeld20 January 200118 December 20065 years, 332 days (7 years, 29 days total)RepublicanIllinoisGeorge W. Bush (2001–2009)
22Robert Gates18 December 200630 June 20114 years, 194 daysRepublican (cross party)TexasGeorge W. Bush (2001–2009)
Barack Obama (2009–2017)
23Leon Panetta1 July 201126 February 20131 year, 240 daysDemocraticCaliforniaBarack Obama (2009–2017)
24Chuck Hagel27 February 201317 February 20151 year, 355 daysRepublican (cross party)Nebraska
25Ash Carter17 February 201520 January 20171 year, 338 daysDemocraticMassachusetts
26Jim Mattis20 January 20171 January 20191 year, 345 daysIndependentWashingtonDonald Trump (2017–2021)
Patrick M. Shanahan Acting1 January 201923 June 2019173 daysIndependentWashington
Mark Esper Acting24 June 201915 July 201921 daysRepublicanVirginia
Richard V. Spencer Acting15 July 201923 July 20198 daysRepublicanWyoming
27Mark Esper23 July 20199 November 20201 year, 109 daysRepublicanVirginia
Christopher C. Miller Acting9 November 202020 January 202172 daysRepublicanIowa
David Norquist Acting20 January 202122 January 20212 daysRepublicanMassachusettsJoe Biden (2021–2025)
28Lloyd Austin22 January 202120 January 20253 years, 364 daysIndependentGeorgia
Robert G. Salesses Acting20 January 202525 January 20255 daysIndependentRhode IslandDonald Trump (2025–present)
29Pete Hegseth25 January 2025Incumbent1 year, 82 daysRepublicanMinnesota

Succession

Presidential succession

The secretary of defense is sixth in the presidential line of succession, after the secretary of the treasury and before the attorney general.

Secretary succession

On 10 December 2020, President Donald Trump modified the order of succession for the office of Secretary of Defense in Executive Order 13963. The order of succession is:

#Office
1Deputy Secretary of Defense
2*Secretary of the Army Secretary of the Navy Secretary of the Air Force
3Under Secretary of Defense for Policy
4Under Secretary of Defense for Intelligence and Security
-Chief Management Officer of the Department of Defense**
5Under Secretary of Defense for Acquisition and Sustainment
6Under Secretary of Defense for Research and Engineering
7Under Secretary of Defense (Comptroller)
8Under Secretary of Defense for Personnel and Readiness
9Deputy Under Secretary of Defense for Policy
10Deputy Under Secretary of Defense for Intelligence and Security
11Deputy Under Secretary of Defense for Acquisition and Sustainment
12Deputy Under Secretary of Defense for Research and Engineering
13Deputy Under Secretary of Defense (Comptroller)
14Deputy Under Secretary of Defense for Personnel and Readiness
15*General Counsel of the Department of Defense Assistant Secretaries of Defense Director of Cost Assessment and Program Evaluation Director of Operational Test and Evaluation Chief Information Officer of the Department of Defense
16*Under Secretary of the Army Under Secretary of the Navy Under Secretary of the Air Force
17*Assistant Secretaries of the Army Assistant Secretaries of the Navy Assistant Secretaries of the Air Force General Counsel of the Army General Counsel of the Navy General Counsel of the Air Force
*Order of Succession is determined by the seniority of officials in their role.
**Office dissolved on January 1, 2021.

Notes

See also

Citations

General sources

Federal law

Directives, regulations and manuals

Further reading

Primary historical sources

Online sources

  • . Office of the Secretary Defense, Director of Administration and Management, Directorate for Organizational & Management Planning. Archived from on 7 May 2013.
  • Farkas, Evelyn (22 April 2025). . Times Union.

External links

U.S. order of precedence (ceremonial)
Preceded byScott Bessentas Secretary of the TreasuryOrder of precedence of the United States as Secretary of DefenseSucceeded byPam Bondias Attorney General
U.S. presidential line of succession
Preceded bySecretary of the Treasury Scott Bessent6th in lineSucceeded byAttorney General Pam Bondi