Why do liberals keep referring to this illegal war? What is so illegal about it?

They're just mad because they don't understand how things work. We never officially declared war...in fact, the US hasn't officially declared war since WWII. Congress gave it's authority to use military force to the President who declared the use of force as our only viable action after the UN dragged it's feet on pressuring Saddam to comply with the UN resolutions it already had in place (you know, the ones he gave the finger to and did what he wanted anyway) and to cooperate fully with inspectors...which he did not. Funny everyone cries about not having backing from the UN for use of force; but no one mentions how the UN was totally inept at controlling Saddam after he broke sanction after sanction for YEARS. Yea....lets wait for them to pull their head out of their 4th point and make a decision; that shouldn't take long.