تبیین نشانگان قدرت و تأثیر آن بر سیاست خارجی آمریکا در قبال ایران

Introduction
In traditional thinking of international relations, power was a one dimensional concept emphasizing on mandatory and structural force regardless of important influence of technology on power. It is very excessive and profound in concept of power. Indeed, power as the ability to do and to influence others is the essential concept in foreign policies of states to initiate and change many political events. There are two approaches to the concept. The first believe that the power is goods that can be achieved and be its owner. The second approach says that no one can be the owner of the power. 
The power has two hard and soft layers. Military and economic forces as hard power can compel others to change their positions. The soft power is getting what we like by attracting not by punishment or award. During the years after Islamic Revolution of Iran, actions of America have frequently endangered national security of Iran. During the past 7 decades, Iran and USA have been faced with up and downs in their relations. From strategic unity to disconnection of relations and military disputes are in history of the relations of these two countries.  Purpose of this research is to identify changes in tools of power and force exertion and its effects on American foreign policies against Iran.
 
Methodology
This research has a descriptive analytical method and the data needed for this study have been gathered from document resources. The hypothesis of this research is “USA in order for general diplomacy attempts to employ new mechanisms of soft power tools against Islamic Republic of Iran (IRI)”. The indicators of power in USA foreign policies against Iran are different in administrations of Carter, Reagan, Bush (the father), Clinton, Bush (the son), and Obama.  Thus, the policies are analyzed differently in each administration.
 
Results and discussion
In fact, since the Islamic Revolution of Iran in 1979 the foreign policies of USA against Iran were hostile actions. In the first decade after the revolution the principal policies of USA were military approaches to exterminate the new regime. With a failure of the USA in application of military forces and hard powers against Iran, this country initiated its attacks applying soft power tools. The failure of America in applying hard tools of power and the advent of information and communication technologies with profound changes in the world lead to application of soft tools of power by USA against Iran. Hegemonic behavioral pattern of America is based on principle of American mission or American exceptionalism by which it can have soft and hard intervention.
Some of up and down relations of USA and IRI are including military occupation of Iran by USA during World War II, support of Iran in front of Soviet Union, coup against the public administration of Mossadegh, pressure for appointment of some governments, assignment of gendarmerie role to Iran in the region according to Nixon doctrine, attempt to exterminate the new government after revolution, conquer of American embassy in Iran, support of Iraq in attack against Iran, disconnection of diplomatic relations, clandestine efforts for reconstruction of relations, limited military battle in Persian Gulf, devastation of passenger plane of Iran and threats after that, exertion of boycotts against Iran, new efforts again for reconstruction of relations, threats for military attack to Iran, naming Iran in the list of lawbreaker and rebel countries, two sides debates about Iraq, making international pressures on nuclear case of Iran, efforts for revival of negotiations, and virus attack to Iranian computer systems especially that of atomic power plant.
 
Conclusion
It can be concluded that American presidents did not stopped their actions against Iran. These were by different concepts such as human rights, democracy, and American mission. The real manifestations of USA behavior in foreign policy can be seen in strategic actions based on hard tools of power. Recently, the government emphasize on value concepts as sources of power to exert their policies. It also can be said that USA has continued its value oriented actions against Iran using different tools of power appropriate to the global conditions in each time.