According to Tom Ricks at Foreign Policy, the Obama administration is pushing out celebrated Marine General James Mattis from CENTCOM early because of internal battles over the White House’s Middle East strategy:

Why the hurry? Pentagon insiders say that he rubbed civilian officials the wrong way — not because he went all “mad dog,” which is his public image, and the view at the White House, but rather because he pushed the civilians so hard on considering the second- and third-order consequences of military action against Iran. Some of those questions apparently were uncomfortable. Like, what do you do with Iran once the nuclear issue is resolved and it remains a foe? What do you do if Iran then develops conventional capabilities that could make it hazardous for U.S. Navy ships to operate in the Persian Gulf? He kept saying, “And then what?”

National Security Advisor Tom Donilon in particular was irked by Mattis’s insistence on being heard. I cringe when I hear about civilians shutting down strategic discussions.

The Mattis-Donilon disagreements weren’t just about Iran. Other issues on which Mattis was pushing the White House to think deeper and harder, I am told, were “Afghanistan, concerns about Pakistani stability, [and] response to the Arab spring.”