In the battle against the Islamic State (IS), it seems clear that some forces rallying under the umbrella of Iraq's Popular Mobilization Units have direct ideological and organizational links to the Iranians. The affiliation to a foreign country raises a red flag as to what role and influence these forces eventually could hold.
These foreign-linked forces are mostly former militias that were founded through direct Iranian support, either during the Iran-Iraq War or after 2003, as Iran attempted to support the Iraqi resistance against the United States. Most notably among these groups are the Badr Organization, Asa’ib Ahl al-Haq, the Hezbollah Brigades and Saraya al-Khorasani.