This thesis is a study on Turkey's quest for a Western alliance between the years 1945 and 1952 within the framework of alliance theories. Neither of these theoretical explanations provide a sufficient answer to the question of "why did Turkey ally with the Western bloc but not with the Soviet bloc or choose neutrality?" This thesis argues that Turkey desired to join NATO because of external and internal reasons. Regarding the external reason of Turkey's alliance with the Western bloc, it is commonly argued that because of the 'Soviet threat' Turkey entered NATO. However, the argument ofthis thesis is that this was not the external reason of Turkey's quest for a Western alliance, because there was no 'Soviet threat' against Turkey, but only demands in order to realize the historic Russian desire to control the Straits and ensure access to the Mediterranean. Therefore, a continuous Soviet 'war of nerves' against Turkey was conducted but came to nothing. The major external reason of Turkey's entrance into NATO was lessons of the past, namely the diplomatic and military isolation, which was very costly to the Ottoman Empire. After WW II, the Turkish officials, coming from the Ottoman tradition. and having had the experiences of the Ottoman era were suspicious that Turkey could again be a bargaining point between the great powers. Thus, Turkey as a newly established state and a weak power vis-a-vis the Soviet Union and Western countries, could guarantee its security only by tying itself as well as the Western powers into a military alliance. The domestic reason of Turkey's alliance with the Western bloc was the state policy of Westernization, which was its desire to divorce itself from the Arabic sphere of culture and tradition, and its full integration into the Western world as an equal, modern, and industrialized state within the Western world. The achievement of industrialization depended on the continuation of US military and economic aid to Turkey. And, by joining NATO, Turkey could distribute the costs of high military expenditures to foreign all_ies by which it could complete its civil industrialization program by redirecting its domestic budget.