As someone who supports military action in Iraq, albeit by a far different route than the one that got us here, if there is not significant evidence that Hussein was continuing his efforts to obtain nuclear weapon capability, this will be a huge mistake.
While chemical and biological weapons are pernicious and horrible, the only real reason to fear that we couldn’t contain and deter him is if he would obtain nuclear weapons. My standard is relatively low–I’m not looking for evidence he could have weapons in a year, but in the forseeable future.
I expect to find evidence of an ongoing nuclear program, but if not, I’ll be happy to admit this was an immoral exercise. At the same time, nuclear capability amongst rogue states is a legitimate reason for military intervention. The question in alternative cases such as North Korea or, say, Pakistan, is whether we can act effectively. In North Korea, that doesn’t appear to be the case.
It could be the case in Iran, but that would seem to be most effectively dealt with by an Osirik type raid.