This article examines the role of security approach in challenging Tehran-Baku relations by analyzing political and economic factors in their bilateral relations. The article centers on finding an answer to the question that what constitutes the main cause of unfriendly approach in relations between the two states between 1991 and 2009. The main hypothesis of this article is that emphasizing security in bilateral relations by Tehran and Baku is the main factor in shaping this situation after the disintegration of the Soviet Union. Theoretical framework of the article is constructivism. Keywords: Security, Economic Interests, Political Relations, Constructivism, Iran, Azerbaijan, Caspian Sea
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