Although Afghanistan is predominately Sunni Muslim (80 percent, roughly 27 million people), it does have a sizeable Shia minority, which accounts for nineteen percent of the population or roughly 6.2 million people.
The Hazara, a Persian-speaking ethnic group which is concentrated mainly in central Afghanistan, with major communities present in western Afghanistan, Iran, and Pakistan, constitutes a large portion of Afghanistan’s Shia.
The Taliban, for its part, backed Sunni Islamist militants who were launching attacks against the Iranian regime.
In 1998, Taliban forces captured Mazar-e Sharif in northern Afghanistan from Dostum and massacred thousands of Hazara civilians, in addition to nine Iranians with diplomatic credentials.
Other important leaders included Uzbek warlord Abdul Rashid Dostum and Tajik warlord Ismail Khan, a member of Rabbani and Massoud’s Jamiat-e Islami.
Iran, along with Russia, provided arms and funding to the Northern Alliance throughout the civil war, while Pakistan and Saudi Arabia supported the Taliban.
Incensed at the killing of its citizens and the Taliban’s horrific treatment of Shia minorities, Iran amassed a quarter of a million troops along the border with Afghanistan and threatened to invade.
Wary of a Sunni-fundamentalist Pashtun state on its eastern border, Iran viewed the rise of the Taliban in 1994 and their seizure of Kabul in 1996 as a serious security, ideological, and economic threat.
The Baluch are another ethnic group that lives in Pakistan, Afghanistan and Iran.
The Baluch constitute two percent of the Iranian population or roughly 1.3 million people.
Iran has a population of 66.4 million and it is one of the world’s only Shia-majority states, with Shia Muslims comprising 89 percent of the population or 58.6 million of people.
Iran also has a Sunni Muslim minority, which accounts for nine percent of the population or 5.9 million people.