From the Document: "Recent U.S.-Turkey tensions and increased Turkish cooperation with Russia have raised questions about Turkey's commitment to NATO and overall strategic orientation. To meet its security, economic, and energy needs, Turkey cooperates with the United States and several other countries whose respective interests may conflict. Events in Syria and a 2016 coup attempt in Turkey appear to have led Turkey's president Recep Tayyip Erdogan to act more independently from the United States and cultivate closer ties with Russia and its President Vladimir Putin. Turkey's large, diversified economy and increased political and military profile gives it significant regional influence, but also has contributed to rivalries with other U.S. partners such as Saudi Arabia, Egypt, Israel, Cyprus, and Greece."
CRS Report for Congress, R44000
Congressional Research Service: https://crsreports.congress.gov/