Turkish forces like these training on the western Syrian border near Idlib in January 2019 have massed for an offensive into northeastern Syria, where Kurdish militias have cooperated with U.S. forces to counter the Islamic State.
The withdrawal of U.S. troops in the face of an impending incursion by Turkish forces into northeastern Syria will significantly decrease the risk of a clash between them. Turkey appears determined to take action against the Syrian Democratic Forces (SDF), a U.S. ally dominated by Kurdish People's Protection Units (YPG), which have cooperated in the fight against transnational terrorism in the region. Both the Turkish operation and the U.S. withdrawal will come with a cost. The Islamic State is likely to try to take advantage of any major clash between the Turks and SDF to reconstitute itself there. Meanwhile, by abandoning the SDF, the United States will find it more difficult to persuade other groups to risk strategic alignment with Washington. The United States and Turkey have had a long-standing policy divergence over the fate of northeastern Syria.
