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U.S. Department of Defense

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Department of Defense
United States Department of Defense Seal.svg
Secretary:Pete Hegseth
Annual budget:$589 billion (FY2017)
Total employed:2.8 million (2016)
Year created:1949
Official website:Defense.gov



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Executive Departments of the United States

Executive Departments
Department of StateDepartment of the TreasuryDepartment of DefenseDepartment of JusticeDepartment of the InteriorDepartment of AgricultureDepartment of CommerceDepartment of LaborDepartment of Health and Human ServicesDepartment of Housing and Urban DevelopmentDepartment of TransportationDepartment of EnergyDepartment of EducationDepartment of Veterans AffairsDepartment of Homeland Security

Department Secretaries
Marco RubioScott BessentPete HegsethPam BondiDoug BurgumBrooke RollinsLori Chavez-DeRemerRobert F. Kennedy Jr.Scott TurnerHoward LutnickSean DuffyChris WrightLinda McMahonDoug CollinsKristi Noem

TheDepartment of Defense (DoD) is responsible for providing military force to ensure the nation's security. Established in 1949, it is the oldest and largest executive department of the United States federal government, employing more than 2.8 million individuals as of December 2016. The stated mission of the department is "to provide the military forces needed to deter war and to protect the security of our country." Major divisions of the department include the United States Army, Navy, and Air Force. The department is based out of the Pentagon, located in Arlington County,Virginia.[1][2]

In September 2025, PresidentDonald Trump (R) issued anexecutive order titledRestoring the United States Department of War, which added "Department of War" as a secondary title for the DoD.[3]

Pete Hegseth is the current secretary of defense.Click here to read more about the confirmation process for Trump's Cabinet nominees.

History

In 1789, the War Department was formed, which paved the way for the creation of the Department of Defense. In 1790, the Coast Guard was created. In 1798, the Department of the Navy was created. In 1947, the National Military Establishment was created to unify the military branches. In the same year, the War Department was replaced and became the Department of the Army. The Department of the Air Force was also created in 1947. The Army, Navy, and Air Force were then placed under control of the secretary of defense. According to the Department of Defense's website, "In 1949, an amendment to the National Security Act further consolidated the national defense structure by withdrawing cabinet-level status from the three Service secretaries. The National Military Establishment was then renamed the Department of Defense."[1]

The Pentagon

The Pentagon on Sept. 11, 2002, taken by Angela Stafford, U.S. Air Force

The Pentagon is the headquarters for the Department of Defense. Construction of the Pentagon began on September 11, 1941, and it officially opened on January 14, 1943. It was believed to be a short-term necessity during World War II; however, as the United States continued to expand its military presence throughout the world, the Pentagon remained the headquarters for the Department of Defense. It is one of the world's largest office buildings with triple the amount of floor space of the Empire State Building inNew York City.[4][5][6]

On September 11, 2001, the Pentagon was the target of a terrorist attack. According to The History Channel, "American Airlines Flight 77 crashed into the Pentagon’s first floor west wall at 9:37 a.m. Traveling 529 miles per hour at the time of the impact, the hijacked Boeing 757 made a gash 30 yards wide and 10 yards deep, puncturing the three outer rings of the building. The resulting fire raged for 36 hours, and by the time it was extinguished, 189 people were dead: 135 Pentagon workers and 64 people on the plane (including the five hijackers)."[4]

Mission

The Department of Defense website states:

The mission of the Department of Defense is to provide the military forces needed to deter war and to protect the security of our country.[7]
—U.S. Department of Defense[1]

Leadership

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The president is the commander-in-chief of the armed force and is responsible for the decisions made regarding the United States' national defense. The president coordinates with the secretary of defense and the National Security Council to decide security needs, as well as necessary plans of action. Those policies are then delegated by the office of the secretary of defense.[8]

The secretary of defense oversees the military departments, the chairman of the Joint Chiefs of Staff, and the unified commands. According to the Department of Defense's website, "The military departments train and equip the military forces. The Chairman plans and coordinates military deployments and operations. The unified commands conduct the military operations."[8]

Recent Secretaries of Defense
Secretary of DefenseYears in officeNominated byConfirmation vote
William S. Cohen1997-2001William Clinton99-0
Donald H. Rumsfeld2001-2006George W. BushNA
Robert M. Gates2006-2011George W. Bush95-2
Leon E. Panetta2011-2013Barack Obama100-0
Chuck Hagel2013-2015Barack Obama58-41
Ashton Carter2015-2017Barack Obama93-5
James Mattis2017-2019Donald Trump98-1
Mark Esper2019-2020Donald Trump90-8
Christopher C. Miller2020-2021Donald TrumpNA
David Norquist (acting)2021-2021Joe Biden-
Lloyd Austin2021-2025Joe Biden93-2
Robert Salesses (acting)2025-2025Donald Trump-
Pete Hegseth2025-presentDonald Trump51-50


Historical Secretaries of Defense
Secretary of DefenseYears in officeNominated byConfirmation vote
James V. Forrestal1947-1949Harry TrumanN/A
Louis A. Johnson1949-1950Harry TrumanN/A
George C. Marshall1950-1951Harry Truman
Robert A. Lovett1951-1953Harry Truman
Charles E. Wilson1953-1957Dwight Eisenhower
Neil H. McElroy1957-1959Dwight Eisenhower
Thomas E. Gates1959-1961Dwight Eisenhower
Robert S. McNamara1961-1968John F. Kennedy
Clark M. Clifford1968-1969Lyndon JohnsonN/A
Melvin R. Laird1969-1973Richard NixonN/A
Elliot L. Richardson1973Richard Nixon81-1
James R. Schlesinger1973-1975Richard Nixon91-0
Donald H. Rumsfeld1975-1977Gerald Ford95-2
Harold Brown1977-1981James CarterN/A
Caspar W. Weinberger1981-1987Ronald Reagan97-2
Frank C. Carlucci1987-1989Ronald Reagan91-1
John TowerDisapprovedGeorge H.W. Bush47-53
Richard B. Cheney1989-1993George H.W. Bush92-0
Les Aspin1993-1994William ClintonN/A
William J. Perry1994-1997William Clinton97-0

Note: Votes marked "N/A" represent voice votes or unrecorded votes. Missing votes will be filled as they are researched.

Organization

Office of the Secretary of Defense

The office of the secretary of defense is primarily in place to be the government liaison of the department. The department develops policy, manages resources, provides oversight, and exchanges information with other government entities both domestic and foreign. Additionally, the office provides oversight of defense agencies and field activities.[9]

Office of the Inspector General

The inspector general's office of the Department of Defense is an independent office in the department charged with auditing and investigating programs and operations of the department.[9]

Joint Chiefs of Staff

The Unified Command Plan establishes the missions and geographic responsibilities among the combatant commanders.

The Joint Chiefs of Staff advise the president and secretary of defense on military matters relating to their respective departments.[9]

Unified Combatant Commands

Commanders of the Combatant Commands carry out the missions assigned by the president and secretary of defense. The directives of the president and secretary of defense are passed down to the commanders by the chairman of the Joint Chiefs of Staff.[9]

Military Departments

The departments of the Army, Navy, and Air Force are organized under their own secretaries and follow the direction of the secretary of defense. The secretary of defense updates the department secretaries on operations and activities regarding their responsibilities.[9]

Organizational chart

DOD org chart.jpeg

Budget

See also:Federal policy on the budget, 2017-2020

Noteworthy events

President Donald Trump (R) issues executive order adding "Department of War" as secondary title

See also:Executive Order: Restoring the United States Department of War (Donald Trump, 2025) andDonald Trump's executive orders and actions, 2025

On September 5, 2025, PresidentDonald Trump (R) issued an executive order titledRestoring the United States Department of War, which added "Department of War" as a secondary title for the Department of Defense.[10] The order said, "The name 'Department of War,' more than the current 'Department of Defense,' ensures peace through strength, as it demonstrates our ability and willingness to fight and win wars on behalf of our Nation at a moment’s notice, not just to defend. This name sharpens the Department’s focus on our own national interest and our adversaries’ focus on our willingness and availability to wage war to secure what is ours."[11]

In order to formally change the name of an executive department, congress would need to pass legislation to authorize the change. Trump's executive order instructed Secretary of DefensePete Hegseth to submit to the president a recommendation with a legislative proposal to officially change the name.[12]

Recent news

The link below is to the most recent stories in a Google news search for the termsUnited States Department of Defense. These results are automatically generated from Google. Ballotpedia does not curate or endorse these articles.

See also

External links

Footnotes

  1. 1.01.11.2U.S. Department of Defense, "About the Department of Defense," accessed December 5, 2016Cite error: Invalid<ref> tag; name "aboutdod" defined multiple times with different content
  2. dmdc.osd.mil, "DoD Personnel, Workforce Reports & Publications," December 31, 2016
  3. BBC, "Trump rebrands Department of Defense as Department of War," September 5, 2025
  4. 4.04.1History.com, "Pentagon," accessed July 3, 2013
  5. Historical Office of the Secretary of Defense, "History of the Pentagon," accessed July 1, 2013
  6. Pentagon Tours, "Facts," accessed July 3, 2013
  7. Note: This text is quoted verbatim from the original source. Any inconsistencies are attributable to the original source.
  8. 8.08.1Defense.gov, "Department of Defense 101 Sections," accessed December 5, 2016
  9. 9.09.19.29.39.4Department of Defense, "Directive Number 5100.01," December 21, 2010
  10. BBC, "Trump rebrands Department of Defense as Department of War," September 5, 2025
  11. White House, "Restoring the United States Department of War," September 5, 2025
  12. Military.com, "Trump Gives DoD ‘Secondary’ Name as Department of War, Circumventing Congress," September 5, 2025
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