During the last decade and simultaneously with the increase of oil price in global markets, a new trend of US energy policy is being shaped in order to reduce US dependence on Persian Gulf oil and gas resources and to move towards energy self- efficiency through an increase of using non-conventional resources (Shell). The questions of this article are the followings; to what extent the exploitation of non-conventional energy has been effective in the implication of US energy self-sufficiency? What has been the impact of exploiting non-conventional energy resources on the importance of the Persian Gulf in US energy security strategy? The hypothesis of this article is that an increase of using non-conventional energy resources has been effective in the reduction of US dependence on Persian Gulf petroleum and can make this country a future rival for traditional energy producers. Decreasing US traditional interventions in Middle East as well as growing inclination to Asia- Pacific region, is a noticeable sign of changing importance of the Persian Gulf for US energy security strategy. Using neo-classic realism, the author tries to scrutinize US energy security policy as a part of its macro strategy of foreign policy.