To Roy's point, the idea that the US can go anywhere in the world and transform a dictatorship into a democracy seems ill-concieved, especially now.
I've held the notion that unless an oppressed populace is ready to fight and die for their freedoms all by themselves, they probably arent ready to handle those freedoms presented in any other manner. I'd put Iran way ahead of Iraq on the list of potential democracies. If oppressed people are ready to lead their own revolution against tyranny - I say help them out. This was clearly not the case in Iraq.
The US had better learn the difference here, or many unfortunate situations will follow this one.