There are different opinions about why we went to war. The story about Iraq having weapons of mass destruction seems to hold less and less water every day, and that there was a conspiracy to create a reason to go to war for some reason, to hide some other big story, to benefit Halibuton, etc. Personally, though, I believe that conspiracies make for great movies, but they rarely work out in real life, and the bigger they are they more likely they are to be blown. You can't get much bigger than going to war.
As far as benefitting Haliburton, the US didn't need to go to war to make that company lots of money. All they needed to do was create some lame energy bill that would pump money to them, and it would almost certainly not have garnered as much attention to the relationship between the Whitehouse and HAL as the war has.
As far as covering something else up, coverups are done to preserve the reputation of the leader. A war like this is CERTAIN to cause so much scrutiny that both the thing you were trying to cover up AND any shenanigans that were used to instigate the war would be uncovered.
Put yourself in GW's position. You continually tell the American people and the world that Iraq has WMDs for months, and months and months, you go toe to toe with the UN for what appears to be a shoddy inspection job, and ultimately kick them out so you can go in and do the job yourself. So you DO kick them out, overthrow the government and undertake a massive campaign to look for the WMDs. And you find none. Do you think it's going to be acceptable to say "oops, sorry" while knowing all along that there were not any to be found? I'd say GW was guilty of getting some bad intelligence but should be commended for putting his reputation, presidency and the lives of American soldiers in jeopardy for doing what he thought was right to defend the nation that he is responsible for. That is not an easy task.
So, there were no WMDs and that does mean that we went in and took over, killed people and broken things for the wrong reason. If we had done nothing and been right about the WMDs, we would likely have experienced a terrible attack. If we did nothing and were wrong WMDs, nothing may have happened. Or Saddam may have utlimately started production again, who knows?
We did what we did because we thought we were doing the right thing at the time. It's terrible that so many people have died on both sides. But, we are where we are. We broke it, so we bought it. We are stuck, obligated to see this operation through to the end. Leaving now would thrust Iraq into a much darker situation than they have now. That is how governments like the Taliban get started.
