The mechanism of strategy for diplomacy water right Iran in Hirmand River

Border Rivers, as one of the most important natural terrain, are always the source of many differences in relations between states. The Hirmand River is the main artery of the Hamoon Lake, the borderline between Iran and Afghanistan, which has caused many border controversies between the two countries to this day. Failure of Afghanistan's to adhere to 1973 agreement to provide the water right of the Hirmand River, and hence the land of Hamoon, as a lake that Sistan's life is dependent on, has exacerbated the increasing challenges in the Sistan region. There has been a lot of negotiation between Iran and Afghanistan. Authors intend to answer the question of what are the strategies of diplomacy for providing the water right to the Hirmand River between Iran and Afghanistan. In the framework of game theory, in the first stage, the Hirmand Water Crisis should be considered as an important priority in the field of Iranian policy. Then, in the process of negotiations between Iran and Afghanistan based on diplomacy, the rationality of actors, Afghanistan’s access to the Chabahar port and the provision of the Hirmand water right as the point of equilibrium and the best option for both countries.