The Democrats seem congenitally incapable of understanding that force has not just the effect of disarming the immediate enemy, but has a deterrent effect on others similarly situated. Iraq was not attacked randomly. It was attacked as part of a clearly enunciated policy — now known as the Bush Doctrine — of targeting, by pre-emptive war if necessary, hostile regimes engaged in terror and/or refusing to come clean on WMDs.
Mullah Omar did not get the message and is now hiding in a cave somewhere. Saddam did not get the message and ended up in a hole. Gaddafi got the message.