U.S. troops are currently stationed at three locations in Syria. The first two, the so-called Green Village and Mission Support Group Conoco, are located in Deir ez Zor province, just east of the Euphrates River. The third site, the small al Tanf garrison, is approximately 300 miles to the south, straddling the Iraq-Syria-Jordan tri-border area. Some 1,000 U.S. personnel operate in Syria, about 3 1/2 years after the Islamic State’s territorial caliphate lost its last chunk of land.