Understanding 1973 the Helmand Treaty by Invoking Rules of Interpretation According to Vienna Convention 1969

Hamoun international wetlands possess social, economic, cultural, protective, and ecological values. As the common heritage of mankind and according to the rules of international environmental customary law, these wetlands have an undeniable right from the Helmand River Basin water resources. Due to the vital values of Hamun wetlands, this paper aims to interpret the 1973 Helmand Treaty in order to find out what is the Hamoun wetlands water right in the 1973 treaty. Accordingly, the 1973 Helmand Treaty is interpreted based on the Vienna Convention on the Law of Treaties (1969). Results reveal that the environmental demands of the Hamoun wetlands have not been considered in the subject and context of the treaty. It is necessary to provide the Hamoun wetlands water rights, which has been neglected in Iran and Afghanistan hydropolitical interaction for more than 115 years. Therefore, it must be paid attention to that the riparian states which have a customary commitment to supply the environmental demands shall provide guaranteed environmental water rights for the Hamouns wetlands.