Iranian officials and Shiite authorities in Najaf reacted in June 2014 to the rapid advances of the Islamic State (IS) and its conquest of Iraqi cities by quickly organizing paramilitary forces. The Quds Force of Iran led by Qasem Soleimani quickly established dozens of paramilitary groups, mostly Shiite ones, to prevent IS from further expanding its forces. And during the past three months, the Shiite paramilitary forces, alongside the Iraqi army, started a series of offensive operations and managed to take back certain important cities. including Ramadi and Tikrit.

However, defeating the IS forces in Iraq is only a short-term goal for these Iran-led Shiite groups. They have negotiated with, and have put political pressure on, the Iraqi government to buy themselves legitimacy. Iraqi Prime Minister Haider al-Abadi officially announced that Hashid Shaabi Popular Mobilization Units) “is an official political party and a pillar of the Iraqi government.” Therefore, a budget has been allocated for Hashid Shaabi in the 2015 Iraqi budget. Hashid Shaabi forces number between 60,000 and 90,000.

The majority of the members of the Popular Mobilization Units are Twelver Shiites and thus listen to the fatwas issued by the Shiite authorities in Najaf and Iran's Supreme Leader Ayatollah Ali Khamenei. The name is somewhat similar to the name of the Iranian political-military force Sazman-e Basij-e Mostaz'afin (Organization for Mobilization of the Oppressed). The Basij was established in 1980 by the order of Ayatollah Ruhollah Khomeini with the aim of creating a 20-million member organization.

The Basij in Iran has 11 million volunteer members and 1 million active members from various backgrounds, including students, university students and government employees. The Basij in Iran is a subdivision of the Islamic Revolutionary Guard Corps (IRGC) and has defined specific tasks for itself. Among these tasks are “fulfilling Ayatollah Khomeini’s orders regarding the creation of international resistance units, creating necessary defense abilities among ordinary people, promoting abilities necessary for massive military operations and aiding the government.”