Comparative evaluation of America's threats in dealing with Iran

Security threats are parts of international political realities. Countries with strategic goals focused on changing the status quo، or not synchronized with the big powers objectives and regional actors are subject to security threat. The Islamic Republic of Iran is among countries with geopolitical threat. These countries are subject to conditions and interacting with actors who have different security and strategic objectives. Iranian security situation in the historic circuit of the last hundred years has indicated such a situation. In the period after the Islamic Revolution victory we have witnessed a «combined threat» of national security that is caused by ideological and strategic components of the Islamic Republic. Great powers have sought to control Iran>s security environment، while regional actors like Iraq، Saudi and Israel are doing a great effort to limit and deal with Iran>s securityapproaches. Such a process although different، has continued in the 21st century. In this article the U. S. security threats against Iran>s strategic objectives during George Bush and Barack Obama will be compared. To explain the matter، U. S. national security doctrine in these two stages is used. On the other hand، behavior patterns and strategic positions of the U. S. and itsallies in the framework of politics and international institutions will be considered. Political literature used by the U. S. rulers and strategists shows that there are some aspects of the threat، confrontation and coping in the two mentioned historical periods. These threats were proposed by a more aggressive literature during the Bush era، while the possibility of threat to become operational was limited. Security threats during Obama has a more flexible literature compared to Bush era but the possibility of threat to become operational has increased. In this paper، based on «defensiverealism approach»، comparison of the American threats during the Bush and Obama has been explained.