The Iraq war didn't go wrong in one day, It was a combination of mistakes by both the pentagon and the military, with micromanagement and politics thrown in. This combination is what led to the false reasons for the war and its bungled aftermath.

http://www.nytimes.com/2006/07/25/books/25kaku.html

Interestingly the review doesn't mention that an entire chapter is dedicated to the times bungling of the WMD story, which did more to convince the public and put pressure on the democrats than any other event.

EDIT: I know the book is a bit old, but I thought I'd post it here, because it is a really good source.

Its in the past. I wish this whole thing never happened. From 9-11 on, just wish it would have never happened. And for what?

From the past, we dig out a better future. We shouldn't make the same mistakes again.

Great fiction. Totally unrealistic though.

Great fiction. Totally unrealistic though.

Fiction ?

Sure, whatever helps you sleep at night.