This probably off-topic here, but since you asked....
Going back to the response after September 11, which must be the genesis for this discussion. After Afghanistan was attacked and the Taliban toppled, Bush gave a speech. I think it was January 2002. It may or may not have been the State of the Union. In that speech he laid out his strategy concerning the war against the terrorists. Besides the typical you're with us or against us, if a country harbors terrorists, they are just as guilty, rhetoric, there was something else. He said something on the order of there needed to be a sea change in the middle east, that Madrasas could not be the only option. That hate could not be the only lesson available. I think this gives a glimmer of what Iraq was meant to be.
If you were going to take the offensive in the middle east, actually address the over-whelming hatred against the US that exists there, how would you do it? What could you possibly do to change it? Even a long shot. Clearly, what Clinton did, did not work. So, what else? Give them what they want and just leave? Order all commercial enterprises and US government installations shuttered and leave? That's not practical. So what?
The order of the day was a neo-con Hail Mary. You have to understand neo-cons worship at the alter of Democracy. I think they have a bit too much faith in that concept, but be that as it may, they believed they could flip a country make it a "shining city on a hill" make it an example. A choice for the restless young men of the middle east. Not immediately of course, but when all was said and done. Remember Bush told us this was a 50 year war. (Afghanistan is one battle in the war, Iraq is another battle in the war).
The question was which country? Iran or Syria? Both members of the "Axis of Evil," both terror supporters in their own rights. Saudi Arabia, Egypt, Jordan and the various Emirates dismissed because they were allies. Yeman? Too irrelevant. Other north African states too far on the periphery of the middle east, besides leverage could work on them (as in Libya). What about Iraq?
A country that lies in the middle of the middle east. A country with a secular background, less religious than other countries. A country with a strong, educated work force and some oil wealth. A country that had been weakened by sanctions for over 10 years.
Strategic Advantages:
Taking Iraq drives a wedge between Iran and Syria. It isolates Iran because we have Turkey and Turkmenistan in the north Occupied Afghanistan on one side, Occupied Iraq on the other. The US Navy controlling the Persian Gulf on another border. Perfect position to monitor one part of the Axis of Evil and add pressure to their government all around.
Syria is similarly isolated. Turkey to the north. Occupied Iraq, Israel only Lebanon and its puppet government was friendly, though that changed.
Taking Iraq meant instantly removing one malefactor from the middle east puzzle and at a minimum neutralizing it while we occupied it. With a little luck, it flips completely and we have another friendly country providing an axis across the middle east of Israel, Jordan and Iraq of friendly nations. Note how Saudi Arabia isn't in the list.
Reasons for war besides the above sited abbreviated list of strategic advantages:
The sanctions were falling apart. (France was openly advocating for the removal of sanctions. Most other European countries were just ignoring them). The oil for food program was a corrupt joke. The Iraqi military routinely fired on allied planes patrolling the no fly zones. Without continued sanctions, Iraq would once again become resurgent adding one more problem into an already problematic middle east.
The question then was do we remove the sanctions and hope for a new casus belli or do we go with what we have or think we have? (It would have been pie in the sky to think that Saddam was going to just be a good citizen, so that was not an option to consider).
My question was, why not tell the people what we are doing and why. Why use the WMD BS to justify the war. But, this was probably someone's bright idea that this is an easy mark. Everyone knew he had WMD, the hard part was making it look immediately dangerous. The only thing worse than the execution of the run up to war was the execution of the immediate aftermath of the military campaign. But, I think I'll stop here. I promised a why did we do Iraq essay, not a review of the entire war.
Ok, go ahead and fire away.
