Analysis about the Nature of Iran and Pakistan relation

The relations of Iran and Eastern neighboring countries always have had many challenges and opportunities and we can see outcomes of these relations in eastern border of Iran.Iran and Pakistan relations have shaped so in a long time .This research tries to answer to this question: why a long time of economic cooperation between Islamic Republic of Iran and Islamic Republic of Pakistan have not spill over to security era and have not declined border's challenges and threats. This question has formed the causal - analytic nature of the article. According to hypothesis of the article, characteristics of a failed state and Interference of neighboring regional and post regional powers are the main obstacles for spill over of Iran and Pakistan economic cooperation to security areas. The article uses Barry Buzan security dilemma and Furen prier dilemma theories. Comparative study of these three theories is another characteristic of this article.