Turkey, a staunch US ally and NATO member during the Cold War, experienced a transformation of its domestic and foreign policy in the last decade. It pursued a more independent and assertive foreign policy in the neighboring region, leading the critics to charge Turkey with abandoning the Western alliance and to question its commitment to strategic partnership with the United States and the EU. This dissertation uses a series of case studies on Turkey’s foreign policy in the Middle East and the Eurasia region to answer the question of whether the recent changes in Turkish foreign policy represent a fundamental reorientation of the country away from the Western alliance and to examine the dominant factors driving Turkish foreign policy during this period. The study concludes that Turkey’s foreign policy transformation in the last decade represents a significant change in the direction of autonomy, but not a fundamental reorientation of the country away from the West. The study also finds that while international factors played an important role in preparing the ground for Turkey’s foreign policy change, domestic factors, particularly Turkey’s economic interests, its new foreign policy elite and their vision, and Turkish public opinion, have been the main drivers of its foreign policy change.