But there's a much more basic reason to crush Saddam Hussein's regime. The Islamic world -- mainly the Arab Islamic world -- needs to realize that it has failed. Medieval Islam cannot compete with liberal capitalism either economically or culturally. Unfortunately, that message has taken several hundred years to filter through. There is nothing like cataclysmic military defeat to teach the lesson more rapidly.
One could point at the examples of Japan and Germany after the Second World War. But the Muslim world provides its own case study. Ottoman Turkey only began to pay attention to Western science and organization after its first serious military defeats at the hands of Austria and Russia in the 17th and 18th centuries.
The US needs to destroy Saddam Hussein's regime because he's a bad man, sure, because he may conceivably be connected with Al-Qaeda, because he's developing weapons of mass destruction, because a friendly Iraq would alter the balance of power in the Middle East, sure, because of all of that. But the US needs to destroy Saddam Hussein's regime mainly because the West needs to humiliate the Arab world, and dispel the Islamic millenial fantasy.
He's right of course, and I suspect (and hope) the Bush Administration has thought of all this. It's just politically incorrect to say it.
But why? The people who would object are always saying that it's a good learning experience when the United States is humiliated.