According to Stratfor, “The U.S. military announced Nov. 16 that it has withdrawn its forces supporting the Turkish-backed rebel operation in northern Aleppo.”
The U.S. is not pleased with Turkey’s continued focus on attacking Kurdish forces. Turkey’s actions are distracting from the primary U.S. objective of pushing the Islamic State from Raqqa, Syria.
By removing U.S. support, Russian and Syrian loyalist forces no longer face a deterrent from moving further north towards the Turkish front line. This leaves Turkey alone and dangerously exposed in northern Syria.