The following is the Aug. 31, 2018 Congressional Research Service report Turkey: Background and U.S. Relations.
From the report
Turkey, a NATO ally since 1952, significantly affects a number of key U.S. national security issues in the Middle East and Europe. U.S.-Turkey relations have worsened throughout this decade over several matters, including Syria’s civil war, Turkey-Israel tensions, Turkey-Russia cooperation, and various Turkish domestic developments. The United States and NATO have...
https://news.usni.org/2018/09/20/report-congress-u-s-turkey-relations-2