US foreign policy goals are self serving like every other country. And it has supported lesser of two evils many times (like a non communist dictatorship vs a communist one).

I don’t think the Iraq war was to establish democracy, it was to get rid of a dictator hostile to the US at a time when after 9/11, the US decided to it would not tolerate further aggressions. But a byproduct of that policy has been the establishment of a democracy and historically the US considered that democracies as natural allies and therefore the more the better.

In practice, just the act supporting the lesser of the two evils has brought so much more evil.

If you want to do good, fine, but make sure you are smart about it and actually achieve that aim. The US has shown that its not good at this, regardless of intentions, they should just refrain from action until they get their shit together.