The diplomatic dustup reflects a reality about US-Turkish relations today. As excited as Erdogan may have been about the end of the Obama Administration and the beginning of the time of Trump, the major points of contention remain what they were.
Erdogan blames longtime bogeyman Fetullah Gülen, a Turkish cleric who lives in Pennsylvania, for instigating last year's failed coup. But Gulen still hasn't been extradited to Turkey, and the United States remains determined to use Kurdish forces to attack the Islamic State rather than relying on Arab troops in the Syrian Defence Forces.
Meanwhile, Turkey, which backs the opposition in Syria, worked with Russia and Iran to set up de-escalation zones, a controversial plan about which US Defence Secretary James Mattis warned, "the devil's in the details".
Despite tensions over the Kurds, Trump is still more Erdogan's cup of tea than his predecessor.
After Turkey held a deeply flawed and internationally-criticised referendum to strengthen Erdogan's political power - a vote the Organisation for Security and Cooperation in Europe described as unfree and unfair - Trump called Erdogan to congratulate him.
Plenty of Turkey watchers described Trump's dismissal of FBI Director James Comey, who was leading an investigation into Trump's potential ties to Russia, as being straight out of Erdogan's playbook. (The Turkish President has jailed thousands and silenced media in the months after the coup attempt.)
But personal preferences aside, Turkey views the Kurdish situation as a near-existential threat - meaning the question of lethal aid for the YPG could tear asunder already strained relations between two Nato allies.
Next week, Erdogan will be able to press the point in person, when he meets Trump at the White House.
- Foreign Policy