The Worst or the Best Treaty? Analysing the Equitable and Reasonable Utilization Principle in the Legal Arrangements of the Helmand River

Abstract After protracted conflicts, Afghanistan and Iran agreed on a treaty in 1973 to share the waters of the Helmand River. However, this legal arrangement became a source of controversy over its equitable and reasonable utilization principle. The 1973 Helmand River Water Treaty reflects a history of legal and political controversy and strongly contrasting views, with some labelling it the “worst” treaty and others the “best”. This paper scrutinizes the history of legal arrangements of the Helmand River within its underlying political context to search for evidence of the aforementioned equitable and reasonable utilization principle. The findings indicate that the 1973 Treaty provides a grey space for legality and illegality, being a greatly restricted instrument to uphold the principle of equity. Examination of the principle of equity in the 1973 Treaty contributes to developing constructive controversy over the Helmand River and offers valuable lessons for other international watercourses facing similar challenges.