WASHINGTON – Army Secretary Dan Driscoll submitted his resignation to President Donald Trump on Monday following months of friction with Defense Secretary Pete Hegseth over the direction of the service and the ouster of senior Army officers, ending a 19-month tenure marked by an unusually public split at the top of the Pentagon.
Driscoll told colleagues he would leave the post effective Sept. 3, according to U.S. officials briefed on his decision, making him the latest senior defense official to depart since Hegseth took office in January 2025. The White House did not deny the resignation, with spokesperson Anna Kelly issuing a statement praising Driscoll’s work.
“Secretary Driscoll has been highly effective in advancing President Trump’s agenda to Make America Strong Again at the Department of the Army by providing outstanding leadership during historic military operations, restoring an emphasis on readiness and lethality, assisting with negotiations between Russia and Ukraine, and more,” Kelly said.
The split between Driscoll and Hegseth had deepened in recent weeks, according to people familiar with the matter. The two clashed over the firings of senior Army officers and the pace of acquisition reform, including a low-cost counter-drone program Driscoll championed. Multiple U.S. officials said the tension had reached a breaking point in recent days, with Driscoll weighing whether to step down before Labor Day.
Driscoll, 47, a former Army Ranger who deployed once to Iraq, was confirmed by the Senate in February 2025 on a 66-28 vote. He entered the role with an unusually broad portfolio: in addition to running the Army’s roughly 450,000 active-duty soldiers, he concurrently served as director of the Bureau of Alcohol, Tobacco, Firearms and Explosives until April. He was a close ally of Vice President JD Vance and traveled to Ukraine last year as part of the administration’s effort to broker a ceasefire and to study drone warfare on the modern battlefield.
His departure leaves the Army effectively leaderless at the top. Hegseth fired Army Chief of Staff Gen. Randy George in April and has not nominated a replacement, meaning the service has gone four months without a confirmed senior uniformed officer in its top post. Since taking office, Hegseth has also presided over the dismissal or early departure of Air Force Gen. Charles “CQ” Brown as chairman of the Joint Chiefs of Staff, Chief of Naval Operations Adm. Lisa Franchetti, Army Vice Chief of Staff Gen. James Mingus, and Army Gen. Chris Donahue, commander of U.S. Army Europe and Africa.
The Pentagon referred questions about Driscoll’s resignation to the Army. A Pentagon official said Sean Parnell, an Army veteran and former political operative now serving as Assistant Secretary of Defense for Public Affairs, is among the candidates under consideration to replace him.
During his tenure, Driscoll pushed an aggressive acquisition-reform agenda, including the launch of FUZE, a $750 million venture-capital-style program intended to move concepts to prototypes within 70 days, and a new effort to mass-produce low-cost interceptors capable of defeating low-cost drones. Both initiatives put him at odds with parts of the traditional defense industry.
The resignation lands as the administration is in the fifth week of a war with Iran and as U.S. forces face a rapidly evolving drone threat on multiple fronts, raising fresh questions about continuity at the top of the Army’s civilian leadership.