What Does The Secretary Of Defense Do?

Learn more about the Defense Secretary, Mark Esper, and how the Department of Defense works.
Secretary of Defense Mark Esper

Secretary of Defense Mark Esper

What is the role of the Secretary of Defense?

The Secretary of Defense presides over the entire Department of Defense and functions as the principal defense policymaker and advisor reporting directly to the President of the United States. Importantly, the defense secretary acts as the principal program evaluations executive, and advises the president and Congress on which programs they recommend be expanded, curtailed, or canceled, and provides the corresponding budgetary recommendations. Largely an administrative role, the defense secretary attends meetings, drafts memos, and facilitates management between the president and the Department of Defense.

The Secretary of Defense ranks sixth in the US presidential line of succession, behind the Vice President, Speaker of the House of Representatives, President Pro Tempore of the Senate, the Secretary of State, and the Secretary of the Treasury.

How is the Department of Defense Organized?

Much like any large corporation, the Defense Department is staffed with managers in charge of accounts payable and receivable, human resources and personnel relations, media relations/public affairs, and IT security, all managed in turn by the defense secretary. In addition, the secretary oversees civilian and uniformed managers whose responsibilities can be grouped into three categories with some necessary overlap: liaising, research and development, and military operations.

  • Defense liaison roles include working in weapons and equipment acquisition through private manufacturers and private contractor services, coordinating with Congress for funding its $716 billion budget and oversight, and cooperating with foreign military counterparts in order to maintain formal and informal alliances, and coordinate arms control policies like nuclear non-proliferation and other counter-WMD goals.
  • Research and development management roles are two-fold and encompass strategic and tactical policy planning for future military operations as well as advanced science and engineering technology research like experimental vehicle and weapons testing, and quantum/high energy physics research, headed by the Defense Advanced Research Projects Agency (DARPA).
  • Military operations managers preside over the Defense Department’s intelligence operations including those of the National Security Agency and the Defense Intelligence Agency, offensive and defensive cybersecurity operations headed by US Cyber Command, missile defense and space operations, POW/MIA accounting, special operations, safeguarding and commanding the US nuclear arsenal, and the combatant commands that integrate the Army, Navy and Marine Corps, Air Force, and Space Force. In times of war, the Army and Air National Guard as well as the Coast Guard may be incorporated into the Department of Defense, but currently report to state authorities and the Department of Homeland Security, respectively.
  • The secretary’s most crucial managerial responsibilities associated with the department’s civilian offices involve overseeing the Office of the Under Secretary of Defense for Policy, in charge of short, medium, and long term policy planning, working directly with the uniformed Joint Chiefs of Staff; the Office of the Under Secretary of Defense for Intelligence, overseeing all military intelligence operations; and the Office of the Under Secretary of Defense for Acquisition and Sustainment, in charge of equipment acquisition, scientific research, and operational sustainability planning and innovation. All three offices require budgetary proposals and evaluations to be approved by the Secretary of Defense before being passed on to Congress.
Looking to make a difference? Consider signing one of these sponsored petitions:

Take Action To Protect Voting Rights With The ACLU Sign Now
Demand Equal COVID-19 Economic Support And Healthcare For African Americans Sign Now
Support The Switch To 100% Renewable Energy Sign Now
*Rantt Media may receive compensation from the partners we feature on our site. However, this in no way affects our news coverage, analysis, or political 101's.

History of the Secretary of Defense

Prior to the creation of the role, the Secretary of War presided over the Army and reported to the president, as the Secretary of the Navy oversaw US naval forces and reported to the president as well, with no unified authority until the temporary Allied command structures emerged during World War II. Following the passage and implementation of the National Security Act, the Department of War and the Department of the Navy subsequently were unified to form the Department of Defense. Only after amendments added in 1949, 1953, and 1958 was civilian and uniformed leadership completely centralized and subordinate to the Secretary of Defense, a civilian who reports directly to the President and his responsible for all duties of the department, in addition to serving a principal role on the president’s advisory National Security Council (NSC).

The 1986 Goldwater-Nichols Act removed command authority from the previously highest-ranking commanders of the defense department’s armed forces, the Joint Chiefs of Staff, and transferred that authority to the current unified combatant command structures organized by region, like the United States Africa Command, or by special use, like the Special Operations Command. All military branches are represented inside these command structures and report directly to the Secretary of Defense. The Joint Chiefs now serve as the highest-ranking uniformed advisors to the defense secretary directly and to the president through their membership in the NSC, headed by the Chairman and his deputy the Vice Chairman of the Joint Chiefs of Staff.

List of previous Secretaries of Defense

  • James Forrestal 1947-1949
  • Louis A. Johnson 1949-1950
  • George Marshall 1950-1951
  • Robert A. Lovett 1951-1953
  • Charles Erwin Wilson 1953-1957
  • Neil H. McElroy 1957-1959
  • Thomas S. Gates Jr. 1959-1961
  • Robert McNamara 1961-1968
  • Clark Clifford 1968-1969
  • Melvin R. Laird 1969-1973
  • Elliot Richardson 1973
  • Bill Clements (Acting) 1973
  • James R. Schlesinger 1973-1975
  • Donald Rumsfeld 1975-1977
  • Harold Brown 1977-1981
  • Caspar Weinberger 1981-1987
  • Frank Carlucci 1987-1989
  • William Howard Taft IV (Acting) 1989
  • Dick Cheney 1989-1993
  • Leslie Aspin 1993-1994
  • William Perry 1994-1997
  • William Cohen 1997-2001
  • Donald Rumsfeld 2001-2006
  • Robert Gates 2006-2011
  • Leon Panetta 2001-2013
  • Chuck Hagel 2013-2015
  • Ash Carter 2015-2017
  • Jim Mattis 2017-2019
  • Patrick M. Shanahan (Acting) 2019
  • Mark Esper (Acting) 2019
  • Richard V. Spencer (Acting) 2019
  • Mark Esper 2019-Present

Who is the current Secretary of Defense?

According to his official biography:

Dr. Mark T. Esper became Secretary of Defense on July 23, 2019. He previously served as the 23rd Secretary of the Army. Dr. Esper graduated from the U.S. Military Academy in 1986, and has two advanced degrees from Harvard University and George Washington University. He served more than 20 years in the U.S. Army on active duty and in the reserves as an Army Infantry Officer. Among his awards are the Department of Defense Medal for Distinguished Public Service and the Combat Infantryman Badge. Dr. Esper is a former defense industry executive and senior U.S. Senate staffer who previously served as the Deputy Assistant Secretary of Defense (negotiations policy).

The Rantt Rundown

The Secretary of Defense presides over a gargantuan organization that spends 3% of the US GDP and presents an enormous challenge to wield effectively. The position historically has not been held for long, leading to frequent resignations, including the first secretary, under Truman. Furthering congressional oversight in order to keep Congress well apprised and integrated into the department's decisionmaking may help ease the burdens of the secretary's management duties, as well as incidentally provide greater political cover that may reduce the frequency of resignations.

Join Our Exclusive Community One-Month Free

  • 24/7 Access To The Rantt Community
  • Daily morning and evening news briefings
  • High-minded analysis from industry experts
  • Participate in thoughtful discussions
  • Amplify your voice on social media
  • No trolls. No bots. No ads.
Try Amazon Prime 30-day free trial!

  • FREE delivery, as fast as today
  • Exclusive shopping deals.
  • Get access to award-winning Amazon Originals.
As an Amazon Associate, Rantt Media earns from qualifying purchases. However, this in no way affects our news coverage, analysis, or political 101's.
Find an affordable freelancer or market services of your own on Fivver!

  • Cost-effective freelance work in a wide variety of fields.
  • Quick turnaround times for time-sensitive projects.
  • Easy to use website that makes finding what you’re looking for a breeze.
Rantt Media may receive compensation from the partners we feature on our site. However, this in no way affects our news coverage, analysis, or political 101's.
Rantt 101 // Cabinet / Government / Military