Bush went to war on a claim that Iraq was about to attack us with WMD. When it became clear there were no WMD the honorable thing to do would be to resign. War is serious business, and there is no room for mistakes – or lies. If you go to war over WMD and there aren’t WMD the right thing to do is step aside and let someome else take your place. Simple as that.
But, really, it’s worse than that. More later.