As the Biden administration vows to put an end to America's "endless wars," the United States' military campaign against the Islamic State in Syria stands out as a rare success. Several hundred US Special Operations Forces remain in northeast Syria where they are partnered with the Syria Kurds who played a critical role in defeating the jihadis. But the fallout in diplomatic terms with NATO ally Turkey has been huge. Aaron Stein, Director for Research at the Foreign Policy Research Institute, a think tank in Philadelphia, and the author of "The US War Against ISIS," reflects on this mixed picture