The equities might also look different if we had given the Turks the nod as an exercise in realpolitik, extracting some concessions from them (say, not buying the Russia S-400 anti-aircraft system); instead, we got nothing.

The pullback has managed, astonishingly enough, to alienate both the Kurds and Turkey from the United States.

Usually, given the historic enmity between the two, it’s possible to alienate only one at a time. After we dumped them, the Kurds have fallen into the arms of the Assad regime, while Turkey will be as hostile to the United States as ever, once Congress gets done trying to punish it for its invasion.

Just like Obama’s withdrawal from Iraq, Trump’s pullback in Syria is a belated reaction to the Iraq war.