Iranian intervention in Iraq (2014–present)
The Iranian intervention in Iraq has its roots in the post-2003 invasion of Iraq by the United States and its allies, when the infrastructure of the Iraqi armed forces, as well as intelligence, were disbanded in a process called "de-Ba'athification" which allowed militias with close ties to Tehran to join the newly reconstituted army.
The intervention reached its peak following the advance of the Islamic State into northern Iraq in mid-2014. Iran began to provide military aid to counter the militant advance. Iran provided technical advisers to the Iraqi government and weapons to the Kurdish Peshmerga. Several sources, among them Reuters, believe that since mid-June 2014, Iranian combat troops are in Iraq, which Iran denies.
The Iraqi Shia militias Kata'ib Hezbollah ("Hezbollah Brigades") and Asa'ib Ahl al-Haq ("League of the Righteous"), funded and trained by Iran, fought alongside the Iraqi Army and Peshmerga in retaking territory from ISIL.