Several other links and a few intelligent comments in the thread. Go read it all to be fully informed. I'm not that involved, trusting that the new boss is on the right track. I give hilzoy the last word. She always does better homework than me.
Love that last paragraph [my emphasis] in parentheses.
...I think it's a wonderful choice, and I can't beat Spencer's explanation of why. So I'll just add three more points. First, it's yet another example of Obama getting a very diverse cabinet without ever seeming to pick someone just for the sake of diversity. Second, Obama served on the Veterans' Affairs Committee, so while there might be some areas where he does not know, in detail, who is good and who is not, this is surely not one of them. Third, Obama is clearly courting the military, not by giving into their every whim, or by ceding to them on matters of policy, but by appointing people whom they trust, and who are very, very good.
I think this is very important -- as I've said before, with all Obama wants to accomplish, he needs strained relations with the military like he needs a hole in the head. But Obama's choices to date also raise the serious possibility that he could end (or at least mitigate) the Republican tilt of the senior officer corps. They have already experienced life under George W. Bush, and by all accounts, they did not care for it. But their distrust of Democrats might easily have prevented them from seriously considering drawing the obvious conclusion from Bush and Rumsfeld's trashing of the armed forces. If Obama can get past that hurdle, he could, just possibly, cause a very significant change.
I don't expect that the senior officer corps would go Democratic the way they are now Republican, nor, frankly, would I really want them to. I think that it's bad for the senior officer corps to be overwhelmingly aligned with either party. I would just like the two parties to be on a level playing field, as far as the officer corps goes. Obama might actually achieve that. And that would be a very big deal.
(And it's not as far-fetched as one might think. I've always thought that the military and Democrats have some obvious, if unrecognized, bits of common ground. The military believes in individual responsibility, and expects each of its members to do his or her best, but they also believe that if a member of your unit has a problem, you should of course help him or her to overcome it; that just saying "ha ha, deal with it yourself" is neither a good way to end up with a well-functioning unit nor a decent way to act. And they believe in trying to put their people in the best possible position to succeed, and to do the best job that they can possibly do. Above all, they do not leave their people behind.
The way they think about members of the military is the way we think about members of society.)