The Pentagon is facing another senior leadership shake-up after US Army Secretary Dan Driscoll resigned, ending his tenure after about 18 months amid reported tensions with Defence Secretary Pete Hegseth.
The White House confirmed Driscoll’s resignation on August 31, shortly after reports emerged of a conflict between the two senior officials over the direction of the Army and the removal of senior military leaders.
Driscoll is expected to leave the Pentagon within days, adding to a string of high-ranking military departures during President Donald Trump’s administration, particularly since Hegseth took charge of the Defence Department.
Despite the reported tensions, the White House praised Driscoll’s performance and described him as "highly effective" in advancing Trump’s agenda.
"Secretary Driscoll has been highly effective in advancing Trump's agenda 'to Make America Strong Again' and provided 'outstanding leadership' during military operations," the White House said in a statement given to CBS.
The White House also credited Driscoll with helping strengthen military readiness and taking part in diplomatic efforts aimed at ending the Russia-Ukraine war.
The full reasons behind the reported disagreement between Driscoll and Hegseth remain unclear. However, reports have linked the dispute to differences over Army leadership and the removal of senior officers.
Driscoll was a close friend of Army Chief of Staff General Randy George, who was reportedly asked to resign by Hegseth. George is among several senior military figures who have left their positions during the period of change at the Pentagon.
Other notable departures include Navy Secretary John Phelan, who left in April, as well as Army General David Hodne and Major General William Green.
Since becoming defence secretary, Hegseth has removed more than a dozen senior military officers, including the chief of naval operations and the Air Force’s vice-chief of staff.
Driscoll’s resignation comes as the US military leadership faces growing pressure over changes to command structures, military readiness and the future direction of the armed forces.
At 41, Driscoll was the youngest person to serve as secretary of the Army. He was confirmed on February 25, 2025, becoming the 26th person to hold the position.
As Army secretary, he was responsible for overseeing operations, modernisation and resource allocation for nearly one million active-duty, National Guard and reserve soldiers, as well as more than 265,000 Army civilian employees.
Driscoll previously served as an Army officer after being commissioned in 2007. He was an armour officer with the 10th Mountain Division, where he led a cavalry platoon and deployed to Baghdad, Iraq, in 2009 in support of Operation Iraqi Freedom.
After leaving active military service, Driscoll attended Yale Law School before working in investment banking, private equity and venture capital. His friendship with Vice-President JD Vance, whom he met at Yale, later brought him closer to the Trump administration.
During his time as Army secretary, Driscoll became known as Trump’s "drone guy" because of his support for emerging battlefield technologies and his push to modernise the Army.
He also took on an unexpected diplomatic role, travelling abroad and meeting Ukrainian President Volodymyr Zelensky during efforts to find a path towards ending the Russia-Ukraine war.
His resignation now leaves another senior position vacant as the Trump administration continues its effort to reshape the leadership of the US military.