Thank you for the link. I think there's an argument that the syrian rebels were fighting terrorism before they were themselves terrorists, but I agree that the US should not be involved in the conflict, and definitely shouldn't fund paramilitary groups with the potential to become terrorists. The U.S. now admitting it was a mistake is important though, because the point of sanctions is to force a government to change its policies.

Geopolitics is messy. In the end I don't see any other strategy besides war that could force Irans hand. If the choices are 1. Show the world that purposefully funding terrorism goes unpunished 2. war, or 3. sanctions I think sanctions are the choice that provides the greatest amount of utility, even if they do harm many.