Turkey Is Out of Control. Time for the U.S. to Say So.

Following Turkey’s incursion into Syria, the once unthinkable prospect of a direct clash between Turkish and American soldiers has become alarmingly real. Turkey’s current fight, against U.S.-backed Kurdish troops in the northwestern Syria territory of Afrin, is destabilizing enough. But the real risk will come if Turkish President Recep Tayyip Erdogan follows through on his repeated promises to press further east toward the Kurdish-controlled and U.S.-patrolled city of Manbij. The only way to prevent a conflict is for U.S. policymakers to adopt a clear and tough-minded approach to Turkey now, before things get worse.