Driscoll’s departure follows the ouster of one of his allies from the Army as well as the rollback of a drone program he had championed. Hegseth had suddenly ousted the service’s top uniformed leader, Gen. Randy George, in April, while the Army’s commander in Europe and Africa, Gen. Christopher Donahue, unexpectedly stepped down in June.

Gen. Christopher LaNeve, who has made a meteoric rise under Hegseth, took George’s place as the Army’s acting chief of staff. Under LaNeve, the service is pulling the plug on a drone modernization program. An Army unit based in Europe was building its own drones before LaNeve directed it to end its efforts and return to being a traditional infantry battalion, officials said in August.

Driscoll was a George ally and lamented his departure, along with both Republican and Democratic lawmakers. He told Congress in April that he and his family drove to George’s house following his resignation “and we all gave him a hug.”