The Bush Administration sent people in uniform out to lie for them to make things look really good.
Some people saw this run-up as a product that was being sold to us. Because that was the language the Bush Administration used. When NSA Condoleeza Rice talked about a mushroom cloud, she was basically fear-mongering. There was no good intelligence linking Saddam Hussein to a nuclear weapon. It was all unfounded.
For perspective's sake, although VP Dick Cheney uncritically accepted that the mushroom cloud thing could happen, he was blasé in the belief that UBL intelligence was fake. They lied a lot, and we knew about a lot of the lies early.
There is no reason to look further than the Bush Administration ignoring every waft of reality sifting underneath everyone's nose, to understand that the Bush guys f'd it all up astoundingly.
Putting the blame for any of it elsewhere is just astonishing.