Pentagon general counsel Jeh Johnson, left, at the Senate Arms Services Committee about the "Don't Ask, Don't Tell" policy. (Kevin Lamarque/REUTERS)

Johnson, who has been the general counsel at the Department of Defense since 2009 and was the Air Force’s general counsel under President Bill Clinton, had a tenure marked by controversy. He has defended increased use of drone strikes, oversaw a reform of military commission trials for terrorism suspects, and co-authored the Pentagon’s landmark 2010 report concluding that ending the military’s “don’t ask, don’t tell” policy would not harm military readiness.

In a recent speech at the Oxford Union, Johnson also made headlines when he indicated that the military’s fight against al-Qaeda wasn’t open ended. Our colleague Peter Finn reports that Johnson contemplated the day when the terrorist network is so degraded the U.S. fight against the organization will no longer be considered an armed conflict and terrorism will become — again — a law enforcement matter.

“On the present course, there will come a tipping point . . . at which so many of the leaders and operatives of al-Qaeda and its affiliates have been killed or captured, and the group is no longer able to attempt or launch a strategic attack against the United States, such that al-Qaeda as we know it, the organization that our Congress authorized the military to pursue in 2001, has been effectively destroyed,” Johnson said.

He did not, however, predict when the conflict would end, or that the end of what used to be called the the war on terrorism is in any way imminent.

Johnson is expected to return to the law firm of Paul, Weiss Rifkind, Wharton & Garrison, where he was a partner.