The bar you have set is for anyone to stipulate ANYTHING about ANY other country and have be a moral justification for war. Because, ya'know, short of being omniscient and all, there is no way of knowing if it is true or false.

The cops have a different "bar" of reasonable suspicion for someone with a rap sheet a mile long than they have for someone who has no record of misbehavior. You'll notice we haven't invaded Mexico, or Britain for that matter, which has nuclear weapons. Saddam had a proven record of building WMD, concealing WMD programs (including nuclear), using WMD, and invading other nations with every weapon at his disposal. Unless he suddenly converted to Bhuddism when we weren't looking, only an idiot would assume he had given up his ambitions. A person's past behavior, and a regimes, counts for something when you are trying to predict future behavior. You really don't care if there's WMD there or not, and it will be instructive to see your take on it when they're eventually found.

We can go on like this all day (in fact, I think we have), but I have to live in the real world. To put it simply, the world has two fewer murderous tyrannies in it than it had a couple of years ago, and I see that as a good thing.* According to polls, so does a large majority of America. With any luck in Iran, the record will go up to three pretty soon, and without us having to bring in the tanks.

*If Al Gore was president, odds are excellent that both of them would still be in power.