What Might Have Been
Kevin Drum makes the important point that however bad the intelligence may have been in October 2002, by March 2003 inspectors were on the ground and it was obvious that it had some serious problems. We went to war because Bush decided it would be better to go to war, not because any sort of bad intelligence forced it (a point that can also be made by looking at the chronology). It should also be pointed out that some similar considerations apply to the humanitarian elements of the case for war. The Kurds, as you'll recall, had a pretty decent deal in the until March 2003 -- technically they were subjects of Saddam's regime, but they were de facto independent; protected by Anglo-American airpower and their own lightly armed pesh merga. We could have done what Michael Walzer proposed and simply push for the creation of a similar situation in the Shia south. Then we probably would have found a much more cooperative local population than the one we got, and, in other words, reap most of the humanitarian benefits that the real world had for a fraction of the cost.