In today's New York Times, Jimmy Carter examines whether this is a 'Just war' or 'just a war'. He concludes, point by point, that it is NOT just, ending with:

"American stature will surely decline further if we launch a war in clear defiance of the United Nations. But to use the presence and threat of our military power to force Iraq's compliance with all United Nations resolutions — with war as a final option — will enhance our status as a champion of peace and justice."