The present study analyzes the roles of the United States and the Soviet Union in the Helmand River water crisis during the Second Pahlavi era (1941–1979). Utilizing a historical approach and a descriptive-analytical method, the research relies on documents from the National Library and Archives of Iran (NLAI) and library-based sources. It seeks to answer the following question: What was the role and impact of the US and the USSR in exacerbating the Helmand River water crisis?
The findings indicate that during the Second Pahlavi period, Iran sought to resist water crises stemming from foreign interventions by employing technical, legal, and diplomatic instruments. However, the rivalry between the Soviet Union and the United States in Afghanistan was not merely about development but centered on influence and hegemony. The geopolitical competition between these two superpowers in Afghanistan—manifested through investments in dam construction and the expansion of hydraulic projects—coupled with the Shah’s apprehension regarding the spread of communism in Afghanistan, led the Iranian government to exhibit excessive flexibility toward the Afghans from the 1960s onwards. Furthermore, US mediation in resolving the dispute through the establishment of the Delta Commission provided a framework that served as a pretext for subsequent negotiations between Iran and Afghanistan.