Starting with March 1945, Soviet Union launched an intense anti-Turkish propaganda and war of nerves, confronting Ankara with strategic demands, such as jointly administering Straits’ defense, requesting land/naval bases in the Straits and modifying Turkey’s eastern border. This study is a historical account of what transpired during the tense months extending from March 1945 until September 1946. It mainly employs a Turkish perspective on the developments.In addition to constructing a historically comprehensive picture of the events, this study also aims to argue that Soviet demands from Turkey and the firm American stance towards them played a key role in the start of the Cold War. It concludes that Turkish foreign policy adopted a completely new orientation as a result of the Soviet demands and the perceived threat in them.