After world war two, International system changed to bipolar system and it remained until cjff decade, In some decades international system was tight and the others was loose, that depended on the relation of east and west. In early decades of 1962 when the Cuba's Crise was happened. And a threat of nuclear war appeared but the rationality of two . great power and threat of united state that Crise solved. That happening opened a new horizon in international system whicli called detente. Iran as a country which was in the west bloc, when the system in macro level changed, appeared the change in foreign policy of Iran (In micro level) began relation between. Iran and Russia. In many fields such as . economic, Military. and cultural contract concluded.

In 1350s especially at tile end of the Pahlavi sorvignty with the opposite bloc was the cause of detente, and the changing of view the two great power, made a good opportunity for Iran to have relation with the radical state or the revisionist states. 

Iran, Russia, Bipolar system, Detente, International system, Cold war> Cuba Crise. .