U.S. Air Force Secretary Michael Donley, who worked five years as the service’s top civilian, retired June 21 after decades in public service.

“Mike Donley has always understood … that national security, our future, our country, is beyond and above politics,” Defense Secretary Chuck Hagel said at a ceremony honoring Donley. “And I suspect he was asked more than occasionally, ‘How could you both work in the Bush White House and work as — continued to work as — secretary of the Air Force under President Obama?’”

Until a permanent replacement is nominated by the president and confirmed by the U.S. Senate, Eric Fanning will serve as the acting secretary of the Air Force. Fanning, a Dartmouth graduate, was appointed Air Force undersecretary in April and previously served as deputy undersecretary of the Navy/deputy chief management officer.