The Syrian Democratic Forces (SDF), led by Kurdish forces, appears to be planning a major attack to seize control of the remaining Syrian-Turkish border that is held by ISIS. Although the launch date is still unknown, the plan includes crossing the Euphrates to attack the ISIS held towns of Jarablus and Manbij in northern Syria. Such an attack would deprive ISIS of its last border crossing with Turkey, which is used to smuggle in supplies and foreign fighters. However, this could lead to a confrontation with Turkey, which views the prospect of a contiguous, autonomous Kurdish region along its border with northern Syria as a national security threat.