The bigger problem, said Faysal Itani, a resident senior fellow at the Atlantic Council, is that the U.S. presence in Syria is so small and the hostility to the U.S. troops so widespread that it is hard to see how they can influence events. The United States maintains 2,000 troops in an area the size of Indiana, alongside the Kurdish-Arab alliance known as the Syrian Democratic Forces. The dominant group in the alliance is the Kurdish People's Protection Units, or YPG, which has close ties to the PKK.