free will doesn't adequately explain how a few acting on their free will might negatively impact millions of others. nor does free will account for the ill and evil in the world that isn't caused by man. it can only cover incidents of personal interactions, so its a poor excuse.
"popular opinion" isnt a very good judge of foreign intelligence, and at the time we didnt *know* there were no WMDs. there was no evidence, but the contention was it was being hidden. and most people really wouldnt have given two figs about going off and kicking an old nasty dictator that...