A couple months ago I wrote a post — I’m really too lazy to Google today — arguing that Obama should absolutely positively not appoint a Republican as his defense secretary. And now I’m kind of backing away from that. Keeping Bob Gates as defense secretary has its merits.

Nancy Soderberg and Brian Katulis make a more full-throated case for Gates than I will. But here’s the reasoning, and all of it is political. Getting out of Iraq requires buy-in from an officer corps that could be fairly described as schizophrenic: it wants out of Iraq at some point, but is acutely sensitive to any perceived slight, particularly from an incoming Democratic administration. False moves from an Obama White House will result in politically damaging leaks. Do not underestimate how powerful a narrative the following line could be: Obama is like Bush — he wants to hew to an ideological agenda against the best advice of the professional military. All it takes is a few well-timed leaks to establish that narrative. The damage to an Obama administration that already has to deal with a global financial crisis would be massive.

All of that militates for appointing someone to the Pentagon whom the building trusts. And right now, just as Gates benefited from not being Donald Rumsfeld, Gates’ successor will suffer for not being Gates. I can think of one person who would be both a substantively brilliant pick and would be instantly esteemed by the Pentagon: Jim Webb. But Webb shows every sign of wanting to stay in the Senate. Failing Webb, my choice for Obama’s secretary of defense would be Tony Zinni, but legally, he has to wait 10 years since his 2000 retirement from the Marine Corps before assuming the office. Given all that, retaining Gates for a limited time makes a lot of sense.

For one thing, the gesture shown to the generals and admirals would be instantly understood and very likely reciprocated. Second, Gates is the sort of public servant who would understand that his duty as secretary is to manage withdrawal, not fight it. Third, bringing a Republican on board with withdrawal is both substantively good for implementing the political consensus that the public tells us already exists; and would make it more complicated for the ultras in the GOP to establish the stab-in-the-back narrative that they’ll launch no matter what. And finally, whatever hits the Democratic brand would take by keeping a Republican on board temporarily would be wiped out by the esteem that the Broders of the world would suddenly find for Obama, as well as by the inevitable replacement of Gates by a Democrat.

One last thing. The rumor I hear is that Gates wants to go home. So offering him the job might in fact be cost-free…