The relations reached a new low when Turkish President Recep Tayyip Erdoğan has threatened to shut down two U.S. bases in Turkey recently. This step is in retaliation to passing of bill in US senate approving sanction on Turkey over the S-400 Purchase and the Syria offense.
The major cause of irritants are:
U.S.-Turkey ties began to slump in recent years after US’s refusal to extradite a US-based Turkish Islamic preacher who is accused by Ankara of orchestrating the failed 2016 coup against Mr. Erdoğan. The U.S. decision to arm and assist Kurdish rebels in Syria against the Islamic State was another blow. Turkey sees the People’s Protection Units (Syrian Kurdish militia) that became an American ally in the anti-IS war, as an affiliate of the Kurdistan Workers Party (Turkish Kurdish militia). The Trump administration has already suspended Turkey from the F-35 programme, citing concerns over Russia spying on the fighter jet’s capabilities using the S-400 system’s radar.