Just as the Taliban emerged as a political force in Afghanistan in 1994, it became clear very quickly that their relations with their western neighbor, Iran, were for the most part based on mutual hostility. They were each radical extremes of the Sunni-Shiite divide with their political systems claiming that the head of their movement served as the leader of all Muslims. The Sunni Taliban came from the Pashtun ethnic group in Afghanistan, which represented some 40 percent of the population. Shiite Iran was by far the larger state in terms of population with close to 83 million in 2019; Afghanistan, by contrast, had a population of only 38 million in 2019.
Iran and the Taliban: Bitter Enemies or Potential Partners (jcpa.org)
