Territorial Disputes Between Afghanistan and Pakistan and Their Impact on the National Security of the Islamic Republic of Iran

With the withdrawal of American and ISAF military forces from Afghanistan in 2021 and the occupation of this country's territory by Taliban forces, the security of the eastern borders has once again become one of the primary security concerns for the Islamic Republic. Afghanistan and Pakistan share a border with Iran that spans about 2,000 kilometers and have significant border disputes between them. With the return of the Taliban to power in 2021, their relations will become more complicated, leading to profound consequences for the national security of the Islamic Republic. The main question of the article is "What is the root of the differences between Pakistan and Afghanistan, and how has it affected the national security of the Islamic Republic of Iran?" The hypothesis of the article is formulated as follows: "The main root of the differences between Pakistan and Afghanistan is the Durand border." Because Afghanistan has not recognized this border line, Pakistan has always sought the failure of the central government of Afghanistan. This situation has become the basis for the activities of terrorist groups such as ISIS, the increase in drug production, the continued displacement of Afghans, foreign intervention, and the establishment of the Taliban as an ideological rival of the Islamic Republic. Each of these is a threat to Iran's national security. The findings of the article indicate that Pakistan's strategy in Afghanistan has resulted in the establishment of a dependent, weak, and failed government in the country. The outcome is the development of anti-security platforms for the Islamic Republic of Iran. The data for the article was collected from library resources, magazines, and specialized internet sites, and analyzed using a qualitative approach.