Over the past two decades, Iran’s border regions have been increasingly affected by the hydrological and climatic interventions of neighboring countries; interventions whose consequences extend beyond environmental tensions, impacting the economic and social foundations of these regions. Focusing on the concept of livelihood security, the present study examines the impact of these interventions on the economic development of Iran’s border regions. The theoretical framework relies on livelihood security and Homer-Dixon's theory of ecological scarcity. Using a comparative method, the research examined three cases between 2011 and 2021: Turkey's interventions in the Tigris and Euphrates basin, Turkey and Armenia's interventions in the Aras, and Afghanistan's interventions in the Helmand. The findings indicate that these interventions, by exacerbating natural resource scarcity, have weakened the three main components of livelihood security namely, living standard stability, sustainable access to water and soil, and employment security consequently eroding the productive and economic capacities of the border regions. The reduction of water resources in these regions is not merely an environmental crisis, but entails a chain of economic and social consequences, including income decline, production drop, migration, and labor force depletion, which weakens regional development capacity. The research concludes that the weakening of livelihood security resulting from transboundary pressures has become a structural barrier to economic development in Iran's border areas. Accordingly, strengthening water diplomacy and establishing monitoring and early warning systems are essential requirements for managing this crisis.