I've finally gained the opportunity to read Rajiv Chandrasekaran's Imperial Life in the Emerald Kingdom. I'm only a few chapters in, but already it's horrifying.
More than that, though, it's educational. While everybody is aware that there was little in the way of reconstruction plans, Chandrasekaran is one of the first to highlight the idea that Garner (and to a lesser extent Bremer) were set up to fail. The reason why? That old villian Ahmed Chalabi. The office of the Vice President and the neocons at DoD were absolutely intent on handing over power to Chalabi, but knew that the CIA and State (as well as the old hands at DoD) would vigorously fight the idea. Any attempt to hand over control to Chalabi had to be done through the back door, so they deliberately hobbled Garner and the ORHA, with the hopes that in desperation they'd turn to Chalabi and his exiles for support. That would (so the theory went) legitimize Chalabi and set him up to be the logical successor to Garner.
That, uh, didn't work. Both because Chalabi was completely unsuited to the job and openly mocked in most of Iraq, and because making it happen meant that they had to systematically remove almost every qualified applicant for work in Iraq, because they were either familiar with Chalabi and didn't trust him, or were too close to State and the CIA, or weren't sufficiently loyal enough to the Republican party.
Meanwhile, junior Republican congressional staffers got to be big cheeses in Iraq, and bring that unique brand of governing incompetence that you can only really get from doctrinaire Republicans to the people of Iraq.