Some more Reuters news on Oct 13:
U.S. Defense Secretary Mark Esper said on Sunday the United States was poised to evacuate about 1,000 U.S. troops from northern Syria after learning that Turkey planned to extend its incursion further south and west than originally planned.
That's still somewhat vaguely phrased. I'm not sure that means complete withdrawal of US troops from all of Syria, i.e. how much does "northern Syria" represent in that statement.
But NBC has more detail:
About 1,000 troops will leave the area "as safely and quickly as possible," Defense Secretary Mark Esper told CBS' "Face the Nation" in an interview Sunday. President Donald Trump late Saturday signed off on the order, which would end most of the U.S. military's presence there, two U.S. military officials in the region told NBC News. Only around 300 soldiers would remain in the U.S. military's Al Tanf base in the south, the officials said. [...]
Esper said that the spiraling conflict had become "untenable" for the U.S. military. [...]
U.S. officials told NBC News that the decision to move troops out was largely because Turkish military and proxy forces had set up more checkpoints on the crucial M4 Highway, cutting off the U.S. military's ability to move safely in the northeast and without coming into contact with the Turkish forces or their proxies.
The officials said it was increasingly clear that the Turkish forces were trying to drive the Americans away.
As WaPo reported on the same day regarding the circumstances for this decision:
“This is total chaos,” a senior administration official said at midday, speaking on the condition of anonymity about the confusing situation in Syria.
Although “the Turks gave guarantees to us” that U.S. forces would not be harmed, the official said, Syrian militias allied with them “are running up and down roads, ambushing and attacking vehicles,” putting American forces — as well as civilians — in danger even as they withdraw. The militias, known as the Free Syrian Army, “are crazy and not reliable.”
The were also claims that Turkish forces had deliberately "bracketed" US forces with artillery fire. And in response
According to the unnamed Pentagon official, "shelling by the Turkish forces was so heavy that the U.S. personnel considered firing back in self-defense." However, "instead of returning fire, the Special Forces withdrew once the shelling had ceased."
And news today is that those 1,000 troops are actually going to Iraq instead
All US troops withdrawing from northern Syria are expected to be relocated to western Iraq, Secretary of Defense Mark Esper confirmed.
Mr Esper told reporters that, under current plans, about 1,000 soldiers would be redeployed to help stop the resurgence of Islamic State (IS).
President Donald Trump has previously pledged to bring US troops home. [...]
On a flight to the region, Mr Esper said US forces would be used to "help defend Iraq" and counter an attempt by IS to re-establish itself there.
"The US withdrawal continues apace from north-eastern Syria... we're talking weeks, not days," he said.
"The current game plan is for those forces to re-position into western Iraq."
A senior US defence official cautioned that plans could change "but that is the game plan right now".
And yeah, the plan changed again. The US is now reinforcing with troops the Kurdish controlled oil fields.
Mark Esper told a press conference at Nato headquarters in Brussels that “we are reinforcing our position” in Syria that “will include some mechanised forces”, although he tried to insist the US mission in the country was unchanged.
The goal, he added, was to deny Isis access to the oilfields in north-east Syria, but he would not say how many US troops would remain other than to indicate the number would be fewer than 1,000.
