Given the multilateralism of the international system, this article discusses the importance of Iran’s Eastern strategy, position and role, and points out opportunities, possibilities, and limits of the international system for Eastern policy. The main point here is that the international system in any period has a fundamental influence on the behavior of states and setting norms, therefore, offering a clear understanding of the system can help explain and analyze the international politics and the foreign policy of global and regional powers. The main question here is that what roles Eurasian states as well as Iran will play in shaping the future international system, and how can Iran’s position in this process be defined? The idea presented here is that the alternative trend for shaping the future international system requires greater cooperation between great and regional powers in Eurasia, and without such interactions, the possibility of playing a role in shaping this structure will be severely limited - Iran’s Eastern strategy has been adopted with such a goal. To examine this idea, first the international system in the last three decades will be discussed, then the current trends for shaping the future system will be reviewed, and finally, a discussion on Eastern policy and Iran-Russia cooperation will be presented in the conclusion.