[58][64] It has been labeled the new Iraqi Republican Guard after it was fully reorganized in early 2018 by its then Commander-in-chief Haider al-Abadi, previous prime minister of Iraq, who issued "regulations to adapt the situation of the Popular Mobilization fighters".

[59] These were: According to Faleh A. Jabar and Renad Mansour for the Carnegie Middle East Center, Prime Minister Nouri al-Maliki used these forces to combat the emergence of ISIL and maintain his influence in predominantly Sunni areas.

On 19 December 2016, Iraqi President Fuad Masum approved a law passed by parliament in November that incorporated PMU in the country's armed forces.

The pro-Assad website Al-Masdar News reports that, with this incorporation, the PMU are now subject to the supreme commander of the national armed forces and will no longer be affiliated to any political or social group.

[87][better source needed] On December 11, 2017, the PMU began to be entirely consolidated under the Iraqi Armed Forces, following a call by Ayatollah Ali al-Sistani to integrate.

[62] However, as late as May 2018, this integration had yet to take place, and PMF members remained without the same wages and privileges as soldiers in the regular Iraqi Armed Forces.

[117][118] By early March 2015 the Popular Mobilization Forces appeared to be strengthening its foothold in the Yazidis town of Shingal by recruiting and paying local people.

[59] The PMF are said to have been led on the battlefields by Jamal Jaafar Mohammed, also known as Abu Mahdi al-Muhandis, the head of Kata'ib Hezbollah,[126][127] but the chain of command runs through pre-existing leaders.

Nonetheless, Marja' Ali al-Sistani issued an "Advice and Guidance to the Fighters on the Battlefields" which included a 20 points form of how the PMF should conduct themselves.

[130][non-primary source needed] Alongside Abu Mahdi al-Muhandis, other people in charge of the PMF include Qais al-Khazali, commander of Asa'ib Ahl al-Haq, and Hadi Al-Amiri, the chief of the Badr Organization.

[59] The militias are trained and supported by military advisers from Turkey (for Sunni and Turkmeni troops),[133] Iran, and Hezbollah,[134] including prominent Quds Force figures, such as (until his 2020 death) Qasem Soleimani.

[136] They are also said to have their own military intelligence, administrative systems,[114] a sort of "media war team" that provides morale boosting, battlefield updates and propaganda videos,[137] and a court of law.

[59] According to Faleh A. Jabar and Renad Mansour, the pro-Sistani faction consists of those armed groups formed by Sistani's fatwa to defend Shia holy sites and by paramilitary of the Islamic Supreme Council of Iraq.

According to Al-Monitor, his move was decided in order to give a multiconfessional image to the Forces; however, Sunni fighters began to volunteer even before the al-Abadi's decision.

Adding Sunni fighters to the Popular Mobilization Units could set the stage for the force to become the core of the envisioned National Guard.

[140] It has been observed that the Sunni Arab tribes that took part in al-Hashd al-Shaabi 2015 recruitment are those which also had good relations with Nouri al-Maliki during his tenure as Prime Minister.

[144][145] In March 2023 there was a brief clash between the Babylon Brigades and the Assyrians of Qaraqosh after the former attempted to take control of a base belonging to the Nineveh Plains Protection Units.

[156] This statement was reversed in March 2016, when al-Abadi reportedly rejected calls by Nineveh's provincial council to prohibit Popular Mobilization Forces from taking part in retaking Mosul.

[157] Shia volunteers reportedly entered Al Anbar Governorate on the first days of May 2015, among heavy protests of Sunnite personalities,[158][159] with limited operations continuing in 2016.

[162] Khomeinist PMF militia factions loyal to the Iranian Supreme Leader have been heavily deployed in the Syrian civil war on the side of the Assad regime, often with the stated aim of defending Shi'ite shrines.

For instance, in January 2015, pro-Iran Kata’ib Sayyid al-Shuhada militant group announced the deaths of two of its fighters in defense of Sayyidah Zaynab Mosque in Damascus, and the militia's involvement in the 2015 Southern Syria offensive was documented by the Iraqi TV station Al-Anwar 2.

[165] On the other hand, pro-Sistani and Sadrist PMF militias wary of Iranian influence in Iraq are strongly opposed to the intervention in Syria and have been resisting recruitment attempts made by pro-Iran factions to send Iraqis to die on the side of Assad regime.

In 2020, Asa'ib Ahl al-Haq, a powerful Iran-backed militia, part of the PMF, was designated as a Foreign Terrorist Organization by the United States.

[120] According to some critics in 2015, the Popular Mobilization Forces were not sanctioned by the Constitution of Iraq and nonetheless had a budget and were paid on regular basis by the Iraqi government, whilst the legally established Peshmerga had not received their wages.

[119] Allegedly, clerics from the Najaf Seminary, including Grand Ayatollah Ali al-Sistani, also criticized the monopolistic conduct of Abu Mahdi al-Muhandis.

[138] The Iraqi Police headquarters in the Muthanna Governorate announced that they were in the process of commissioning Popular Mobilization battalions with security tasks in early January 2016.

According to the militia's deputy, Ahmed al-Maksousi, they were hit by artillery fire in Syria's Jamouna area, about 12 kilometers (about 7.5 miles) from the Iraqi border.

[193][194] On 12 March 2020, the U.S. launched air raids against five Kata'ib Hezbollah weapons storage bases across Iraq in retaliation for the 2020 Camp Taji attacks.

[195] On 25 February 2021, a U.S. air raid killed one and wounded four while targeting PMF facilities on the Iraqi-Syrian border in Syria's eastern Deir ez-Zor Governorate.

[198] On 4 January 2024, U.S. airstrikes on PMF's logistical headquarters killed two people, including the organization's deputy head of operations in Baghdad, Mushtaq Talib al-Saeedi, and wounded five others.