The United States is getting ready to ask Syrian Kurds to allow Turkish forces to deploy on the Kurdish side of the Syrian border. It's a move designed to appease Turkey, which has national security concerns regarding the autonomous Kurdish region in northeastern Syria — but the move may not go far enough to please Ankara.
In 2017, I wrote that Turkish President Recep Tayyip Erdogan could not simultaneously manage Washington and Moscow, and that he would eventually be squeezed between them. This is precisely the conundrum now with the controversy over Turkey's desire to purchase both Russia's S-400 anti-aircraft missile system and US F-35 jets. Washington says that if Turkey gets both systems, Russia would gain access to US technology.