Those skeptical of U.S. intervention in the Syrian civil war have long warned that it could escalate into a civilization-warping conflict between nuclear powers. But neither Vietnam nor Afghanistan nor Iraq nor Libya has persuaded today’s hawks to sufficiently weight the unintended consequences that plague all complex military interventions. And there are so many varieties of hawks that are urging action.

The complexity of the civil war in Syria is underscored by the fact that the ascendant pro-war faction inside the Trump administration is composed of Iran hawks. According to reporters Kate Brannen, Dan De Luce and Paul McLeary at Just Security, antagonism toward Iran is causing two officials in the Trump White House to push for broadening the conflict, against the advice of officials at the Pentagon…