An Iraqi insurgency began shortly after the 2003 American invasion deposed longtime leader Saddam Hussein. It is considered to have lasted until the end of the Iraq War and U.S. withdrawal in 2011. It was followed by a renewed insurgency.
The Islamic Revolutionary Guard Corps, also called Sepah or Pasdaran, is a multi-service primary branch of the Iranian Armed Forces. It was officially established by Ruhollah Khomeini as a military branch in May 1979, in the aftermath of the Islamic Revolution. Whereas the Iranian Army protects the country's sovereignty in a traditional capacity, the IRGC's constitutional mandate is to ensure the integrity of the Islamic Republic. Most interpretations of this mandate assert that it entrusts the IRGC with preventing foreign interference in Iran, thwarting coups by the traditional military, and crushing "deviant movements" that harm the ideological legacy of the Islamic Revolution. Currently, the IRGC is designated as a terrorist organization by Bahrain, Saudi Arabia, Sweden and the United States.
The Badr Organization, previously known as the Badr Brigades or Badr Corps, is an Iraqi Shia Islamist political party and paramilitary organization headed by Hadi Al-Amiri. The Badr Brigade, formed in 1982 and led by Iranian officers, served as the military arm of the Supreme Council for Islamic Revolution in Iraq (SCIRI), a Shia Islamic party based in Iran. The Badr Brigade was created by Iranian intelligence and Shia cleric Mohammad Baqir al-Hakim with the aim of fighting Saddam Hussein's regime during the Iran–Iraq War. Since the 2003 US-led invasion of Iraq most of Badr's fighters have entered the new Iraqi army and police force. Politically, Badr Brigade and SCIRI were considered to be one party since 2003, but have now unofficially separated with the Badr Organization now an official Iraqi political party. Badr Brigade forces, and their Iranian commanders, have come to prominence in 2014 fighting the Islamic State of Iraq and the Levant (ISIL) in Iraq. It is a part of the Popular Mobilization Forces.
The Shia Crescent is the notionally crescent-shaped region of the Middle East where the majority population is Shia or where there is a strong Shia minority in the population.
The term militia in contemporary Iraq refers to armed groups that fight on behalf of or as part of the Iraqi government, the Mahdi Army and Badr Organization being two of the biggest. Many predate the overthrow of Saddam Hussein, but some have emerged since, such as the Facilities Protection Service. The Anglo-American invasion of Iraq in 2003 undermined the internal order in the country and brought about, among other things, the establishment of several pro-Iranian militias affiliated with the IRGC's Quds Force. The militias were set up with the purpose of driving the U.S. and Coalition forces out of Iraq and establishing Iranian involvement in the country. Prominent among the militias are Asa'ib Ahl al-Haq, Kata'ib Hezbollah and Harakat al-Nujaba.
After the death of Muhammad in 632, a group of Muslims, who would come to be known as the Sunnis, believed that Muhammad's successor as caliph of the Islamic community should be Abu Bakr, whereas a second group of Muslims, who would come to be known as the Shias, believed that his successor should have been Ali ibn Abi Talib. This dispute spread across various parts of the Muslim world, which eventually led to the Battle of Jamal and Battle of Siffin. Sectarianism based on this historic dispute intensified greatly after the Battle of Karbala, in which Husayn ibn Ali and some of his close partisans, including members and children of the household of prophet, were killed by the ruling Umayyad Caliph Yazid I, and the outcry for revenge divided the early Islamic community, albeit disproportionately, into two groups, the Sunni and the Shia. This is known today as the Islamic schism.
Sheik Ahmed Bezaa Abu Risha is a Sunni leader in the Al-Anbar province, and led the movement of Sunni tribesmen known as the Anbar Salvation Council.
Special Groups (SGs) is a designation given by the United States military to the cell-based Shi'a paramilitary organizations operating within Iraq, backed by Iran. According to the United States these groups are funded, trained, and armed by the Iranian Quds Force, part of the Islamic Revolutionary Guard Corps (IRGC). According to the United States Department of Defense, 603 American troops in total were confirmed to have been killed by IRGC-backed Shia militias during the Iraq War.
Kata'ib Hezbollah —or the Hezbollah Brigades—is a radical Iraqi Shiite paramilitary group which used to be part of the Popular Mobilization Forces, staffing the 45th, 46th, and 47th Brigades. During the Iraq War (2003–11), the group fought against Coalition forces. It has been active in the War in Iraq (2013–2017) and the Syrian civil war (2011–present). The group was commanded by Abu Mahdi al-Muhandis until he was killed in a US drone attack in 2020. Thereafter, he was replaced by Abdul Aziz al-Muhammadawi, as the new leader of the Popular Mobilization Forces (PMF). KH seeks to establish an Iran-aligned government in Iraq, expel American forces from the country, and advance the regional and international interests of Iran in Iraq and the region. The group is responsible for killing hundreds of U.S. soldiers and takes a central part in carrying out attacks against U.S. targets in Iraq and acts as part of the Axis of Resistance. Kata'ib Hezbollah is directly subordinate to Iranian Islamic Revolutionary Guard Corps's (IRGC) Quds Force and operates under its instructions and guidance.
The Axis of Resistance is an informal anti-Israeli and anti-Western political and military coalition led by the Iranian government. It includes the Syrian Arab Republic, Lebanese Shia militant group Hezbollah and various militant groups in Palestine.
The Free Iraqi Army was a Sunni rebel group formed in the western Sunni-majority provinces of Iraq from Iraqi supporters of the Free Syrian Army rebels fighting in the Syrian Civil War. The group aimed to overthrow the Shia-dominated government of Iraq, believing that they would gain support in this from Syria should the rebels be successful in overthrowing Bashar al-Assad. An Iraqi counterterror spokesman denied this, saying that the name is merely being used by al-Qaeda in Iraq to "attract the support of the Iraqi Sunnis by making use of the strife going on in Syria."
The Islamic Republic of Iran and the Syrian Arab Republic are close strategic allies, and Iran has provided significant support for the Syrian government in the Syrian civil war, including logistical, technical and financial support, as well as training and some combat troops. Iran sees the survival of the Syrian government as being crucial to its regional interests. When the uprising developed into the Syrian Civil War, there were increasing reports of Iranian military support, and of Iranian training of the National Defence Forces both in Syria and Iran. From late 2011 and early 2012, Iran's IRGC began sending tens of thousands of volunteers in co-ordination with the Syrian government to prevent the collapse of the Syrian Arab Army; thereby polarising the conflict along sectarian lines.
Anti-Sunnism is hatred of, prejudice against, discrimination against, persecution of, and violence against Sunni Muslims.
The Iranian intervention in Iraq has its roots in the post-2003 invasion of Iraq by the United States and 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.
Hezbollah involvement in the Syrian Civil War has been substantial since the beginning of armed insurgency phase of the Syrian Civil War in 2011, and evolved into active support for Ba'athist government forces and troop deployment from 2012 onwards. By 2014, Hezbollah was deployed across Syria. Hezbollah has also been very active in preventing Al-Nusra Front and Islamic State penetration into Lebanon, being one of the most active forces in the Syrian Civil War spillover in Lebanon.
The Popular Mobilization Forces, also known as the People's Mobilization Committee (PMC) and the Popular Mobilization Units (PMU), is an Iraqi state-sponsored umbrella organization composed of approximately 67 different armed factions, with around 230,000 fighters that are mostly Shia Muslim groups, but also include Sunni Muslim, Christian, and Yazidi groups. The Popular Mobilization Units as a group was formed in 2014 and have fought in nearly every major battle against ISIL. Many of its main militias, in particular the Shias, trace their origins to the "Special Groups", Iranian-sponsored shiite groups which previously fought an insurgency against the United States and the Coalition forces, as well as a sectarian conflict against Ba'athist and sunni jihadi insurgents. It has been called the new Iraqi Republican Guard after it was fully reorganized in early 2018 by its then–Commander in Chief Haider al-Abadi, Prime Minister of Iraq from 2014 to 2018, who issued "regulations to adapt the situation of the Popular Mobilization fighters".
Harakat Hezbollah al-Nujaba, officially the 12th Brigade, is a radical Iraqi Shi'ite paramilitary group that is especially active in Syria and Iraq. It was established in 2013 by Akram al-Kaabi to support Bashar al-Assad in Syria against Islamist rebels. The group is supported by the IRGC's Quds Force, which provides the funding, weapons, and training of its members.
Iran and Saudi Arabia are engaged in an ongoing struggle for influence in the Middle East and other regions of the Muslim world. The two countries have provided varying degrees of support to opposing sides in nearby conflicts, including the civil wars in Syria and Yemen; and disputes in Bahrain, Lebanon, Qatar, and Iraq. The struggle also extends to disputes or broader competition in other countries globally including in West, North and East Africa, South, Central, Southeast Asia, the Balkans, and the Caucasus.
The Baqir Brigade, named after Shia Imam Muhammad al-Baqir, is a Syrian loyalist militia originating in the Aleppo Governorate that fights in the Syrian Civil War. One of the most prominent and largest pro-government militias from the Aleppo area and part of the "Local Defence Forces" network, the Baqir Brigade mostly consists of tribesmen from the al-Baggara tribe that traditionally supported the rule of the al-Assad family despite being mostly Sunni Muslim. Though the militia's fighters thus come from a largely Sunni background, many of them have converted to or are at least strongly influenced by Shia Islam. Indeed, the Baqir Brigade has been noted for its strong connections to the Lebanese Hezbollah, Iran, and various Iraqi Shia militias, and is thus generally considered to be a Shia or "Shi'ified" fighting force.
Akram Abbas al-Ka'abi is the founder and Secretary-General of Harakat Hezbollah al-Nujaba (HHN) in Iraq. Kaabi is a U.S.-designated terrorist who is regarded as one of the main operatives of IRGC's Quds Force in Iraq. He has been an ardent supporter and promoter of Iranian influence in Iraq while being the most outspoken critic of American military presence as he seeks to compel U.S. forces to withdraw completely from Iraq.
Iraq 
Iran (Claimed by Battat, denied by the IRGC)[ citation needed ]
Islamic State of Iraq and the Levant 
People's Mujahedin of Iran 
Free Iraqi Army 
