“American troops landed in the ground war in Syria in late 2015 with a small contingent of Special Operations forces, hoping to forge an alliance with local militias and rebel groups that could fight the Islamic State.
In the months that followed, the number of American troops grew. Their Kurdish and Arab allies, later known as the Syrian Democratic Forces, started ground assaults that would eventually lead to the loss of Islamic State strongholds in the northern cities of Manbij and their de facto capital in Raqqa.
There are currently an estimated 2,000 American troops in Syria, according to the Pentagon. The influx of forces transformed what had been an initial band of commandos in armored pickups into a scaled-down version of the sprawling military presence in neighboring Iraq.”
IR Theory & Practice 