US Troops on the Ground in Syria to Stop Turkish Aggression 

The U.S. and Russia have found themselves teaming up for the first time in the war in Syria — against a country both call an ally: Turkey.

The U.S. and Russia moved this week to block a threatened drive by Turkey to seize Manbij, a town in northern Syria about 40 kilometers (25 miles) from the Turkish border. A U.S. deployment and a Russian-brokered deal with Syrian forces created buffer zones that headed off any Turkish campaign against the Kurdish forces who hold the town — seen by Washington as key allies against Islamic State and by Turkey as terrorists.

Source 

https://www.bloomberg.com/amp/politics/articles/2017-03-08/u-s-russia-counter-erdogan-in-syria-as-fight-scrambles-allies