Throughout our relative few years as a nation, our blood has been spilled around this planet for the benefit of other nations. Our military has carried the weight of the world on it's back. We always have. And as long as we are Americans, we always will. That's what makes us Americans. Willing to fight and die so others can be free. What they do with that freedom is up to them.
You go too far. Freedom may have been the outcome of America's foreign interventions, and you may think that Americans are worth sacrificing to fight for others' freedom, but Americans fought in every single foreign war in which America has been involved for the defense of the nation, not freedom for other countries. Ask any American why we fight before or during any foreign war, and the answer will be almost exclusively self-defense. We did not invade Germany to stop the Holocaust, and we didn't invade Iraq to stop Saddam's rape rooms. We did it to protect ourselves.
And as to 'what they do with it being up to them,' I doubt our Iraqi based forces will stand by and silently assent if the Iraqis vote in a theocracy.