Should the United States have started Iraq war in 2003?

In 2003, U.S. together with allies, especially the U.K., started a war against Iraq. From the perspective of the time point before the war, should the U.S. have started the war?

Limitation: Many more points from the linked procon.org analysis could be added. Nonetheless, two perhaps most salient are covered: weapons of mass destruction and oil.

Arguments for

 * There was information about Iraq developing weapons of mass destruction, a category that includes chemical weapons, biological weapons and nuclear weapons. One should thwart such developments before it is too late. (For instance, one should neutralize Hitler's Nazi Germany before it starts a war, e.g. upon its march into Rhineland.)
 * Spreading democracy to Iraq and freeing Iraqi citizens from the tyrannical dictator Saddam Husein is a good thing.
 * Spreading democracy--if that can be done and maintained--is far from being a sufficient reason to attack a country.
 * If that were any concern then why did the US leave its Kurdish allies for dead in 1975?

Arguments against

 * Preemptive war in the absence of an actual threat against the preemptively attacking countries is questionable.
 * Taking official rationales with appropriate grain of salt and looking at underlying objectively existing interests, especially economic interests, it seems too likely that the real reason for going to war was control and access to oil/petroleum, and waging war over that is not morally justifiable.