Nah we don't. Bush says he is carrying out UN resolutions and the UN says he is not. Bush is doing it for his reasons and that is regime change, oil, or Israel. Reasons matter for moral high ground.
In my opinion, the fact remains that the ball has been solidly in Saddam's court for more than a decade. All he had to do was abide by the deal he made to stop the first gulf war. He cried "uncle" there, not us. He made a deal and then he broke it.
If he would have kept his deal, this would be ancient history. The onus was on him to do as he said.. Not the reverse.
Let me ask you:
Suppose you commit a crime, are caught and cop a plea to get off with community service instead of jail.. THEN, you refuse to do the community service, as you promised.
Are the cops immoral for coming after you? Are they actually the "agressors" in this scenario? Or is it your own fault and something that any reasonable person would have anticipated?