Second Trump Administration – Department of Defense (Department of War)

Nominations and Appointments

Pete Hegseth is the 29th United States Secretary of Defense, commonly referring to himself as the Secretary of War since President Trump’s executive order on the name of the department issued in September 2025.  ¹ Hegseth is a former U.S. Army National Guard infantry officer and Princeton graduate, and is the author of five books, including the 2024 New York Times bestseller The War on Warriors. ¹

Stephen Feinberg is the Deputy Secretary of Defense (alternately Deputy Secretary of War). He was confirmed in March 2025 by the U.S. Senate with a vote of 59 to 40. ² Prior to joining government service, Feinberg founded Cerberus Capital, a global investment firm. He also served as Chairman of the President’s Intelligence Advisory Board between 2018 and 2021 in the first Trump administration. ³

Earl Matthews is the General Counsel of Defense. He was confirmed in July 2025 by the U.S. Senate with a vote of 50 to 47. ⁴ Prior to his current role, he was a Senior Associate Counsel to the President in the Office of the White House Counsel. Before that, he worked full-time at the Department of Defense Transition Team as deputy team lead. Before joining the second Trump administration, he was general counsel and head of business development for Neros Technologies, a manufacturer of unmanned defense systems. Before that, he worked as general counsel and corporate secretary of Albers Aerospace Corporation. Prior to that, he was the president of Veeam Government Solutions, the wholly owned federally focused subsidiary of Veeam Software Corporation. Before that, he served in the first Trump administration as Deputy Assistant to the President and Senior Director for Defense Policy and Strategy on the National Security Council staff. Before that, he was Acting General Counsel/Principal Deputy General Counsel of the Department of the Army. Before that, he worked as Deputy Legal Counsel to the Chairman of the Joint Chiefs of Staff, as Special Counsel to the Director of National Intelligence, as a Special Assistant to the Secretary of Defense and as both an attorney and an intelligence officer at the Defense Intelligence Agency. He served in the U.S. Army in combat operations in Iraq and Afghanistan, earning a Bronze Star, and is as of April 2026 a colonel in the U.S. Army Reserves. ⁵

Kirsten Davies is the Chief Information Officer of the Department of Defense. She was confirmed in December 2025 as part of an en bloc confirmation of Trump administration appointees by the U.S. Senate with a vote of 53 to 43. ⁶ Prior to joining government service, she worked as the chief information security officer (CISO) for Unilever. Prior to that, she worked in technology and cyber roles for The Estée Lauder Companies, Barclays-Africa Group, Hewlett Packard Enterprises, and Siemens. She is also the founder of the Institute for Cyber. ⁷

Dane Hughes is the Assistant Secretary of Defense for Legislative Affairs. He was confirmed in October 2025 as part of an en bloc confirmation of Trump administration appointees by the U.S. Senate with a vote of 51 to 47. ⁸ Prior to joining the second Trump administration, he was a staff member for the U.S. House of Representatives Armed Services Committee. Prior to that, he was the director of strategy for Research Innovations Inc., vice president for government affairs at Deutsche Bank, USA, and vice president at Marsh and McLennan. Prior to that, he served in the first Trump administration as Senior Advisor to the Assistant Secretary of Defense for Asian and Pacific Security Affairs, Policy Chief for the Assistant Secretary of Defense for Legislative Affairs, and Senior Advisor to the Secretary of Defense. He is a U.S. Army veteran with three combat tours and a recipient of the Bronze Star. ⁹

U.S. Air Force General John D. Caine is the Chairman of the Joint Chiefs of Staff. He was confirmed in April 2025 by the U.S. Senate in a vote of 60 to 25. He was commissioned in 1990 through the ROTC program at the Virginia Military Institute and was a fighter pilot, flying the F-16. Prior to becoming Chairman of the Joint Chiefs of Staff, he was the Associate Director for Military Affairs at the Central Intelligence Agency. Between 2009 and 2016, he was a member of the Air National Guard and a serial entrepreneur and investor.

Joe Kasper has served as the Chief of Staff to the Secretary of Defense since January 2025. Kasper was a leading player in the dismissal of three high-ranking officials as part of a leak investigation. Prior to joining the department, Kasper was chief of staff to then-U.S. Representative Duncan Hunter (R-CA) and worked in government relations and consulting. Kasper left the role in April 2025 but continued to support and advise the Pentagon as a special government employee, which limited his work to temporary government jobs for no more than 130 days per year. ¹⁰

Sean Parnell is the Assistant to the Secretary of Defense for Public Affairs. He was appointed in February 2025. Previously, Parnell worked as a senior advisor for Concerned Veterans for America and as a consultant to members of the U.S. Congress. Parnell is a retired U.S. Army officer who led one of the most decorated units in the Afghanistan War. He received two Bronze Stars and a Purple Heart and was forced to retire from the military due to wounds suffered in combat. He wrote the New York Times bestseller Outlaw Platoon about his service in Afghanistan. ¹¹

Michael P. Duffey is the Under Secretary of Defense for Acquisition and Sustainment. He was confirmed in June 2025 by the U.S. Senate in a vote of 51 to 46. ¹² Prior to joining the Pentagon, he was a partner at Equinox Global Solutions. In the first Trump administration, he was an Associate Director for National Security at the Office of Management and Budget. He previously worked in the Pentagon for over a decade as Deputy Chief of Staff to the Secretary; Chief of Staff to the Under Secretary of Defense for Research and Engineering; Special Assistant to the Secretary of Defense for the White House Liaison; and Deputy Director for Data Analysis. ¹³

Elbridge Colby is the Under Secretary of Defense for Policy. He was confirmed in April 2025 by the U.S. Senate in a vote of 54 to 45. ¹⁴ Prior to joining the Pentagon, he was the co-founder of the think tank Marathon Initiative and wrote The Strategy of Denial: American Defense in an Age of Great Power Conflict. In the first Trump administration, he served as Deputy Assistant Secretary of Defense for Strategy and Force Development from 2017 to 2018. Prior to this, Colby worked in a variety of U.S. government roles including for the U.S. State Department in Iraq and held a variety of think tank roles. ¹⁵

Jeff Bornstein was nominated for Under Secretary of Defense (Comptroller)/CFO but did not assume the role. Bornstein was a managing partner at Generation Capital Partners and former chief financial officer of General Electric from July 2013 to October 2017. The White House withdrew his nomination in October 2025 with no public explanation. ¹⁶

Daniel Driscoll is the Secretary of the Army. He was confirmed in February 2025 by the U.S. Senate with a vote of 66 to 28. ¹⁷ He is a former U.S. Army officer who served in Iraq and went into business after leaving the military. He is a member of Iraq and Afghanistan Veterans of America. ¹⁸

John Phelan was the Secretary of the Navy from March 2025 until April 2026. He was confirmed in March 2025 by the U.S. Senate with a vote of 62 to 30. ¹⁹ Prior to entering government service, he was a financier. He left office in April 2026 after infighting with his superiors in the Pentagon. ²⁰

Troy Meink is the Secretary of the Air Force. He was confirmed in May 2025 by the U.S. Senate with a vote of 74 to 25. ²¹ Prior to becoming Secretary, he was Principal Deputy Director at the National Reconnaissance Office. He was commissioned as an Air Force officer in 1988 through the ROTC program at South Dakota State University. ²²