When he spoke to President Trump on the telephone a week ago Friday, Turkish President Recep Tayyip Erdogan’s agenda had not changed from when they met two weeks earlier at the Group of 20 summit in Argentina.

He repeated his inability to understand why the United States was still arming and supporting Syrian Kurdish fighters to conduct a ground war against the Islamic State. To Turkey, which shared a 500-mile long border with Syria, they were a national security threat, allied with Turkish Kurds that even the United States considered terrorists.

The Islamic State, according to Trump himself, had been defeated, Erdogan said. Turkey’s military was strong and could take on any remaining militant pockets. Why did some 2,000 U.S. troops still need to be there?

“You know what? It’s yours,” Trump said of Syria. “I’m leaving.”

...It came at a time when he was feeling a loss of control over a range of issues, from the special counsel’s Russia investigation to the falling stock market and a threatened government shutdown.

According to a version of events in the Associated Press, the US position going into the call was to demand that Turkey stall a planned offensive into Syria aimed at US-backed Kurdish elements of the SDF, which Ankara sees as indistinguishable from the Kurdish insurgency inside Turkey.

“The talking points were very firm,” one of the officials quoted by the Associated Press said. “Everybody said push back and try to offer [Turkey] something that’s a small win, possibly holding territory on the border, something like that.”

Erdoğan responded by saying that Isis had been 99% defeated.

“Why are you still there?” Erdoğan demanded, according to the account.

With the Turkish leader still on the line, Trump asked the same question of his national security adviser, John Bolton, who repeated US policy until then, that the defeat of Isis had to be “enduring”, preventing the possibility of a resurgence.

To the surprise of Bolton and Erdoğan, Trump instantly sided with the Turkish president.

According to the Turkish newspaper Hurriyet, whose account is similar to the Associated Press’s, Trump declared: “OK – do it.” Not hearing an instant response from Bolton, Trump demanded to know whether his national security adviser was still on the line. When Bolton said he was, Trump ordered: “Start the work.”