Summary

Turkey’s decision to purchase the Russia-made S-400 air defense system has driven another wedge between the country and its NATO allies in a period of already strained relations. In response, the United States removed Turkey from the F-35 fifth-generation stealth fighter program, and economic sanctions could also be implemented. Many are now questioning Ankara’s continued membership to the Atlantic Alliance. And while an expulsion remains unlikely, the S-400 issue will still have far-reaching repercussions for US-Turkey relations.