The half-assed intervention leading to a protracted conflict in Syria has arguably been much more damaging to American interests than Iraq was, not to mention screwing up Syria a lot worse than it already would have been. Unless there was some pretty crazy stuff going on beyond the public eye to justify it, it's a strong candidate for America's biggest foreign policy blunder of the century (so far). Actually, I'm struggling to think of something definitely worse since Vietnam, in those terms. It's been (very) low-cost in American lives & money compared to Iraq and Afghanistan, but just horrible for US interests and for general international stability, in the Middle East and Europe, especially, and it hasn't even done Syria any favors to offset that.

Iraq and Afghanistan—either one, on its own—surely did more direct harm to America itself, however, but in sheer foreign-policy terms? Our actions in Syria look really bad from that perspective.

I write that as an Obama voter, and Iraq war protester.

This is another neo-liberal talking point. Its like Saying Libya under Gaddafi was horrible too blah blah. You know how it is like right now?