While I'm on the subject of Bush, I may as well also talk about my own understanding of how we got into Iraq specifically. This was written a long time ago in response to a silly what-if forum war, but the writing conviently allows me to edit and post it here.
Go back to before we had the hindsight of today. Recall that there was substantial fear following 9/11 that our neglect of middle east foreign policy may have meant our gravest threat. In 2002, there was stacks of evidence from unaccounted for weapons that gave the entire global community the impression that Iraq was a rogue state with the will to potentially proliferate their weapons.
As it turned out, Saddam Hussein only thought he had WMDs, hence why he was acting like he had something to hide during the UN Inspections. He was attempting to pay his own internal scientists off so that they'd secure him WMDs, but unbenowst to him (and everyone else), internal corruption within Saddam's own bureaucracy was scamming Hussein out of his money.
Like any do-nothing special interest group, Saddam's own lackey's were giving him false reports of "progress" to the tone of how "we will certainly have toys like nukes and dirty bombs within 5 years Mr. Hussein, provided your continued patronage." These reports would ultimately end up in the world's intelligence community from the CIA to the KGB and, not realizing they were faked by sycophants, ended up putting such intelligence on Bush's desk.
When UN Inspectors arrived, Saddam's lackey's were forced to put on the show of acting like they had research to hide in order to continue Saddam's personal delusion of holding a stockpile of deterrents, fearing his wrath were he to discover that his bureaucracy was essentially doing nothing for the past 13 years. Hence Saddam's arrogant attitude, of speeches pertaining to how he was going to bath Baghdad with American blood by the thousands when they'd attack (using the non-existent WMDs that Saddam thinks he's purchased).
Since every American was pissed off, paranoid, and the thought of kicking some other state's behind was an overwhelming popular sentiment in 2002, I don't blame any president for making that decision. It was not a war over oil (there's plenty of oil on this side of the planet we could tap into if we wanted, its not like all oil in the world exists in the middle east), it was a paranoid war over alleged WMD's that Saddam and the entire Intelligence community thought he had.