List of United States Secretaries of Defense

List of United States Secretaries of Defense
Post	Secretary of Defense
Body	the United States
Insigniasize	120
Insigniacaption	Seal of the U.S. Department of Defense
Department	United States Department of Defense
Incumbent	Lloyd Austin
Incumbentsince	January 22, 2021
Member of	Cabinet
Reports to	President of the United States
Appointer	President of the United States
Appointer qualified	with Senate advice and consent
Termlength	No fixed term
Formation	September 17, 1947
First	James Forrestal
Succession	Sixth

List of United States Secretaries of Defense. The United States Secretary of Defense is the head of the United States Department of Defense, a principal advisor to the President of the United States on military matters, and a key member of the Cabinet of the United States. The position was created by the National Security Act of 1947, succeeding the earlier Secretary of War and Secretary of the Navy. Secretaries have played pivotal roles in conflicts from the Korean War and the Vietnam War to the Gulf War and the War in Afghanistan (2001–2021), while also managing the department through periods like the Cold War and the War on Terror.

List of Secretaries of Defense

The first Secretary of Defense was James Forrestal, appointed by President Harry S. Truman. Notable figures include Robert McNamara, who served during the escalation of the Vietnam War under Presidents John F. Kennedy and Lyndon B. Johnson; Caspar Weinberger, a central architect of the Reagan administration's military buildup during the final years of the Cold War; and Donald Rumsfeld, who served two non-consecutive terms, notably leading the department during the September 11 attacks and the subsequent Iraq War. Recent officeholders include Leon Panetta, Chuck Hagel, and the current secretary, Lloyd Austin. The position requires confirmation by the United States Senate and the secretary oversees the United States Armed Forces, including the United States Army, United States Navy, United States Marine Corps, United States Air Force, United States Space Force, and the United States Coast Guard when it is operating as a service in the United States Department of the Navy.

Deputy Secretaries of Defense

The United States Deputy Secretary of Defense is the second-highest-ranking official in the United States Department of Defense. This position was established by the National Security Act of 1947 and is tasked with assisting the secretary and acting in their absence. Prominent deputies have included David Packard, who served under Melvin Laird during the Vietnam War, and Paul Wolfowitz, who was a key figure in the George W. Bush administration during the planning of the Iraq War. The deputy secretary often chairs high-level committees like the Deputy's Advisory Working Group and works closely with the Chairman of the Joint Chiefs of Staff and the Office of the Secretary of Defense.

Secretaries of the Army, Navy, and Air Force

These are subordinate civilian leaders within the United States Department of Defense. The United States Secretary of the Army, United States Secretary of the Navy, and United States Secretary of the Air Force are appointed by the President of the United States and report to the Secretary of Defense, rather than being Cabinet-level positions. Historically, the roles of Secretary of War and Secretary of the Navy were independent cabinet posts until the reforms of the National Security Act of 1947 and the later Department of Defense Reorganization Act of 1958. Notable secretaries have included Frank Knox, who served as Secretary of the Navy during World War II, and John Lehman, who served under President Ronald Reagan.

Acting Secretaries of Defense

An Acting United States Secretary of Defense temporarily fulfills the role when the secretary is incapacitated, resigns, or is otherwise unable to serve, and before a successor is confirmed by the United States Senate. Succession is governed by the Federal Vacancies Reform Act of 1998 and departmental directives. Notable instances include Robert Gates briefly serving in an acting capacity in 2006 before his official confirmation, and Christopher C. Miller, who served as acting secretary following the resignation of Mark Esper in the final months of the Trump administration. The United States Deputy Secretary of Defense is typically the first in line to assume acting duties.

Timeline of Secretaries of Defense

A graphical timeline typically shows the tenure of each secretary aligned with the President of the United States under whom they served. It visually highlights periods of stability and transition, such as the rapid turnover during the Watergate scandal and the Ford administration, or the unusually long tenures of figures like Robert McNamara and Caspar Weinberger. The timeline often includes major events that defined their terms, such as the Cuban Missile Crisis during McNamara's tenure, the Fall of Saigon under James Schlesinger, and the killing of Osama bin Laden during the tenure of Leon Panetta.

Notes on succession and acting service

The line of succession for the United States Secretary of Defense is established by federal law and executive order, designating the United States Deputy Secretary of Defense as the primary successor, followed by the Secretaries of the Army, Navy, and Air Force, and then the Under Secretaries of Defense. The National Security Act of 1947 and subsequent amendments like the Goldwater–Nichols Act have clarified these procedures. Historical ambiguities were addressed after events like the Assassination of John F. Kennedy, leading to more formalized protocols to ensure continuity of leadership within the United States Department of Defense and the National Command Authority.

Category:United States Secretaries of Defense Category:Lists of American government officials