What a superpower does not do is as important as what it does do. America was content to fund a few rebels but otherwise leave Syria in the hands of others. Assad turned to the Islamic Revolutionary Guard, Hezbollah, and Iran. Russia saved him from reprisal after the gas attack in 2013 and again when rebels neared Damascus in 2015.

By then, Obama had been forced to intervene against the Caliphate established by ISIS in eastern Syria and western Iraq. But some red lines he stuck to. In his speech announcing the counterterrorism campaign in September 2014, Obama pledged, “We will not get dragged into another ground war in Iraq.” Our presence would be limited, our footprint light. Enough to defeat the terrorists, but not enough to make us targets. Or decisively affect the outcome of the Syrian war.

If there is a place where America blinked, where America chose decline, where America’s allies began to worry and America’s retrenchment from Eurasia and pivot to East Asia began, it is Syria. We did so with open eyes and, until the last two weeks, an untroubled conscience. Not wanting to commit the resources necessary to build functioning states, we left Iraq, abandoned Libya, and turned a blind eye to Syria. Not willing to sacrifice Americans on additional fields of battle in the Long War against Islamic terrorism and the religious-political cultures that breed it, we withdrew that presence which guarantees the security of our partners.