truth: PNAC wanted to conquer Iraq since about 1997 or 1998, so that's the most basic and real reason for Iraq - to strengthen US hegemony and world domination by controlling the major oil resources, which of course , drive the world as it currently exists.
history: In the 2002 SOTU speech, Bush put Iraq forward (more prominently than his other axis-of-evil nations) to start rallying public opinion for invasion:
" Our second goal is to prevent regimes that sponsor terror from threatening America or our friends and allies with weapons of mass destruction.
Some of these regimes have been pretty quiet since September 11, but we know their true nature. North Korea is a regime arming with missiles and weapons of mass destruction, while starving its citizens.
Iran aggressively pursues these weapons and exports terror, while an unelected few repress the Iranian people's hope for freedom.
Iraq continues to flaunt its hostility toward America and to support terror. The Iraqi regime has plotted to develop anthrax and nerve gas and nuclear weapons for over a decade. This is a regime that has already used poison gas to murder thousands of its own citizens, leaving the bodies of mothers huddled over their dead children. This is a regime that agreed to international inspections then kicked out the inspectors. This is a regime that has something to hide from the civilized world.
States like these, and their terrorist allies, constitute an axis of evil, arming to threaten the peace of the world. By seeking weapons of mass destruction, these regimes pose a grave and growing danger. They could provide these arms to terrorists, giving them the means to match their hatred. They could attack our allies or attempt to blackmail the United States. In any of these cases, the price of indifference would be catastrophic. "
link From that point up to actual invasion, the Bush* maladministration tried to make the case, and ramp up fear. The IWR points to UN resolutions that Iraq was either actually or supposedly not in compliance with, so the maladministration tried to use those to justify the invasion.
I think the vote on IWR was predicated on the maladministration going to the UN and trying to get inspectors to validate the WMD claims before invading. Once the inspectors were in and not finding anything, the maladministration started saying the WMDs were hidden, inspectors were being lied to etc. - then they kind of had to hurry and invade before the lie was totally exposed.
Whit House draft of IWRone more edit:
The IWR did commit the Bush* maladministration to working with the UN and trying for diplomatic resolution befor einvasion:
"Whereas on September 12, 2002, President Bush committed the United States to `work with the United Nations Security Council to meet our common challenge' posed by Iraq and to `work for the necessary resolutions,' while also making clear that `the Security Council resolutions will be enforced, and the just demands of peace and security will be met, or action will be unavoidable'; ..."
last linkI think in short, that the IWR was
because people were calling bullshit on maladministration plans to invade.
did that help?