Blue Eagle - you could have added to your scenario the 'Bagdhad converted into large glowing piece of glass' gambit.
Of course, as an thoroughly evil refinement of your scenario, we could hit his oilfields with Trident, then raise the price of North Sea Oil to $100 a barrel...
But such flippancy aside, therein lies the nub of the question: if he has WMD (and if not, why have the missing weapons not been found or their destruction properly recorded for external scrutiny??) and as he has already displayed a penchant for employing them, do we sit around waiting for UNMOVIC to find them all, or try to solve the problem?
And if we do that, and if UNMOVIC don't find them, and if he has them and then if he uses them, it'll be no good saying 'See, we told you so!' to President Chirac et al. Now that's an awful lot of 'ifs' that I've put above, but isn't almost everything in international affairs predicated on an awful lot of 'ifs'? The problem is that an alternative scenario to the ultimate use of force if (that word again!) Saddam fails to comply and is in possession of WMD has not been provided.
As for arguments about North Korea and Zimbabwe deserving more attention, I can see the rationale, but can't quite agree with it: the UN has not yet passed resolutions demanding disarmament by North Korea, and been waiting for 12 years for the regime to comply; Uncle Bob has not shown any desire to develop WMD or threaten his neighbours. Both regimes are thoroughly despicable, and we should be doing more than sending Task Force Tatchell to Paris to deal with the latter, but I would respectfully argue that we have to prioritise.
Kim may well do something to change that order, but despite his apparent lunacy, must be well aware that the US (in the form of Clinton) explained that if Kim used WMD 'That would be silly, because his country would cease to exist'...
Now, I'd prefer to see a UN resolution, but not some wishy-washy compromise. It needs to be a 'more time, but with a deadline' resolution. That's to say that if Dr Blix comes back to the UN at a certain specified date and is unable to say 'we have complete co-operation and are now enforcing complete compliance with the resolution', then, sorry, Saddam, but you've had your chance(s). Although the Hitler analogy has been beaten to death with a large stick and mis-applied, its central core retains validity: we did nothing about Hitler's violation of international agreements, (nor Japan's for that matter) and it did far more harm than good in the end.