Afghanistan–Iran relations

Relations between Afghanistan and Iran were officially established in 1935 during Zahir Shah's reign and the Pahlavi dynasty's Reza Shah Pahlavi, though ties between the two countries have existed for millennia. As a result, many Afghans speak Persian, as Dari (an eastern dialect of Persian) is one of the official languages of Afghanistan, and many in Afghanistan also celebrate Nowruz, the Persian New Year.

Relations were negatively affected by the 1978 Saur Revolution and 1979 Iranian Revolution and issues related to the Afghan conflict (i.e. PDPA, Mujahideen, Afghan refugees, and the Taliban), as well as Iran's water dispute and the growing influence of the United States in the Islamic Republic of Afghanistan. According to Deutsche Welle in 2018, an increase in Taliban activity in the border between Iran and Afghanistan suggests a possible cooperation between the Iranian forces and the Talibans. In a 2018 report by the Reuters, Afghan forces at the time accused Iran of presenting the Taliban with arms and money, but Iran denied the accusations. In July 2019, the Iranian government passed a law that provides Afghan nationals with a new chance to get Iranian residency. Afghans with specific scientific and professional achievements and those who have Iranian spouses and children are among those who are qualified to benefit from the law. After the Taliban returned to power in 2021, despite some differences, relations between the two countries have further developed.