I agree with your assessment. There is an added, bitter irony to this situation. We have been bombarded by the media for the last several years with the conventional-wisdom mantra that "although our military and Rumsfeld did a good job toppling Saddam, they failed miserably to plan for the rebuilding".
This is an example of "the Big Lie" in operation. The fact is that just as our troops were putting paid to Saddam's regime in the summer of 2003, Colin Powell and the State Department, with their allies in the CIA, successfully wrested control of the post-Battle of Iraq rebuilding policy away from Rumsfeld and the DOD.
This led to debacles such as the disfunctional Paul Bremer consulship and consequent misjudgements such as the failure to kill al Sadr, our defeat at the "First Battle of Fallujah", and the failure to shut down the Syrian and Iranian terrorist resupply lines when the American people would have still supported it. The military was ready to go into Syria and take out the terrorist supply and training bases there, but the diplomats forbade it. As a bonus, if we had done that, we might have found some of those "non-existent" WMDs in Syria.
As I said, it's a bitter irony that Rumsfeld and our military leadership are castigated for failing to plan for the post-war rebuilding, when the truth is that their plans were quashed and Colin Powell and the diplomats are really culpable.
There's only one Decider.