Many critics have assumed that if President Trump forcefully rebuffed Recep Tayyip Erdoğan over Trump’s decision to withdraw from Syria in the now-famous Oct. 6 phone call, the Turkish president would have backed down.

But Trump, backed up by his defense and state secretaries, insists Erdoğan was not bluffing and was hellbent on launching a clearing operation across his southern border. The goal was to establish a safe zone as a buffer against elements of the Kurdish-led Syrian Democratic Forces that Turkey considers anti-government terrorists.