The Pentagon has very little choice in these things, Congress gets to approve General Officer appointments much like Federal Judiciary ones, (Except it is not just the Senate for the Generals, but both houses) and like the Judiciary, any one of the Congressman with a grudge can end the general's career. It is a stupid and corrupt system, but the General Officers have to put on the kneepads and blowjob the Congressmen unless the political appointees above them actually step up to the plate and run interference...which is never going to happen with a Democrat administration and Murtha, or even any of the Republican Defense Secretaries since Caspar Weinberger.