Politics. Bush wouldn't have had the support of some members of Congress if he hadn't gone to the UN. It also had the effect of clearly defining who was with us and who was against us. That is being borne out now with the present difficulties the UN and Kofi Annan is having with OFF.
It was a dumb resolution that is meaningless. There was no law in plain language referring "We hereby declare war on Iraq" like it used to be the case.
So? Where does it say that specific language must be used?
Just because you don't like the wording doesn't mean it isn't legit.
I am not saying it is not legit. I am also saying it is not a declaration of war. If it was, why didn't it just say so. It talks about preconditions of war set by some international organization which is beyond the control of US law. In essence, the resolution is meaningless. There must not be any reference of the UN when it comes to our foreign policy, except to withdraw from it.