Whilst Bush Jr may have famously come out and declared GW2 over as history shows it was far from over and sadly I believe it still has a very long way to go, whether that be in Iraq or elsewhere.p
Technically he was correct. The conventional forces of Saddam Hussein had been defeated and either captured or had "withdrawn" from battle. There was no cohesive military force remaining in Iraq at a national or even provincial level. The error, if any, in declaring "victory" was the appalling decision to remove all Ba'athists from their positions which served only to put a lot of people with questionable loyalty to "the New Iraq" out of work and thus poor while leaving them with too much time on their hands. It also was an act that succeeded in doing what all the precision bombing that preceded it had, rightfully, failed to do... It destroyed the infrastructure which, in turn, made those with an optimistic view of "The New Iraq" less than happy with their "Liberators".
It's trendy to point the finger at Bush but you have to remember he doesn't come up with all this in a vacuum... Much of what actually takes place begins in the minds of his gaggle of advisors and he makes his decisions on the basis of their "expert" opinion and analysis. The "incredible disappearing WMD's" are a prime example. Bush didn't sit there poring over aerial photos and volumes of intreps... Other people did that and then brought their conclusions to him, (and to his predecessor who believed the reports too and commented publicly on several occasions). His "guilt", if any, lies in his choice of advisors... But then, in the USA, you also need to blame Congress because, over here, many advisory positions undergo a confirmation process by Congress - fail to get the approval of Congress means no appointment.