Economic Relations between Afghanistan and Iran from 1297–1320 SH / 1918–1941 AD

International conditions and the interventions of colonial powers in the domestic affairs of Afghanistan and Iran during the nineteenth and twentieth centuries have been influential. This study examines the nature of economic relations between the two countries during the years 1297–1320 SH / 1918–1941 AD. Moreover, studying contemporary history without understanding the economic and financial situation, and without analyzing the causes and contributing factors of change, is highly incomplete. In essence, the presence of an economic history trend within the field of humanities in both countries remains relatively undefined. Therefore, increased attention to economic history and its perspective within contemporary humanities research is necessary, and recognizing the importance of such studies is by no means insignificant. Afghanistan, a landlocked country, experienced a dominant influence of foreign powers on its economic markets. Most of its commercial goods were exchanged through transit routes controlled by Russia and British-ruled India. This research uses a historical and descriptive method. Information was collected from books, documents, newspapers, and official reports from 1918 to 1941. The focus was on analyzing trade records and political relations between the two countries. This study highlights the historical economic ties between Afghanistan and Iran, providing insights into the key factors that shaped bilateral trade in the early 20th century. This study raises the question of how the economic relations between the two countries were structured, and identifies the most significant internal and regional challenges impacting them. Trade relations between Afghanistan and Iran, as well as with other foreign powers, were shaped by similar political frameworks. Alongside a brief overview of their economic ties, this study addresses various aspects such as the beginning of economic relations, commerce, imports and exports of different types of goods, trade volumes, facilitation mechanisms, customs barriers and challenges, transit debates and their complications. It appears that a lack of attention to economic and cultural relations between Afghanistan and Iran has been influenced by the Helmand (Hirmand) water issue, domestic conditions in both countries, and foreign interventions in their affairs. This neglect by scholars cannot be interpreted as an absence of relations, especially given the presence of documents and records. Books written about the Helmand River, border disputes, and frontier security have rarely addressed the essential aspects of bilateral relations—namely the economic and cultural ties—which today include a high level of commercial exchange and are characterized by shared culture and language. The findings of the study indicate that Afghanistan and Iran sustained consistent trade relations throughout this period. The principal goods exchanged comprised carpets, agricultural products, textiles, and precious stones. The dynamics of political transformations, persistent border disputes, and the involvement of external powers exerted considerable influence on the extent of their economic cooperation. Moreover, border cities such as Herat and Mashhad emerged as pivotal commercial hubs, serving as central nodes in the facilitation of cross-border trade.