Last month’s airstrikes targeting Iran-backed paramilitary groups in Iraq threaten to bring the country back into conflict shortly after the fight against the Islamic State. The coalition of paramilitary groups called al-Hashd al-Shaabi, or the Popular Mobilization Forces (PMF), blamed Americans and Israelis for the attacks, which targeted its weapons depots. Abu Mahdi al-Muhandis, the de facto leader of the PMF, threatened retaliation in coordination with the Iraqi government. The Iraqi government, however, did not support his response and stated that he did not speak on its behalf.

According to our research as part of a newly released Chatham House report, Iraq’s post-Islamic State stability has been based on an understanding between the PMF and the government, or between the de facto and formal leadership. Here’s what a dispute between them could mean for the country.

The PMF and the state

After the Islamic State — also known as ISIS — swiftly captured the Iraqi city of Mosul, then-Prime Minister Nouri al-Maliki brought together seven paramilitary groups in June 2014 to form the PMF and defend Iraq. The PMF has since expanded to include about 50 groups. At the time, Iraqi Shiites, in particular, enlisted in the PMF instead of the formal state armed forces, which had crumbled to a few thousand salafi-jihadi fighters. Over the years, the PMF took on a more formalized role in security, political and socioeconomic affairs. Today, it is recognized as a state actor under the National Security Council (NSC) of the prime minister’s office. However, it does not operate completely under the authority of the state and, as such, has become a hybrid actor, at times cooperating and at other times competing with the state for capability, legitimacy and power. This included, for instance, attempting to provide security or ensuring service provisions where the state could not.

Immediately after Muhandis’s response, Iraq’s NSC and the formal leader of the PMF, Faleh al-Fayadh, issued a letter stating that Muhandis does not speak on behalf of the PMF or the commander of the armed forces. Many were surprised by this rare public dispute between Muhandis and Fayadh, who have for the most part been on the same page.

In Iraq, both the formal state and the de facto authorities need each other

Our findings — based on the cases of Iraq and Yemen — show that when de facto leaders cooperate with the formal bureaucracy, the state is more likely to move toward order. But when the de facto leaders lose their trust in the formal bureaucracy and grow more powerful and legitimate, the state moves toward chaos.

The Iraqi state does not have a monopoly over legitimacy, capabilities or power and, as such, cooperates with the PMF to ensure stability. This was clear during the fight against the Islamic State, especially in the initial years, when the PMF stepped in for the crumbling Iraqi security forces.

However, Muhandis and the PMF also need the formal bureaucracy. For one, state payments make up a significant source of the PMF’s revenue. Moreover, the PMF’s role is legitimized by the state’s backing; it has sought-after official recognition and has been operating under the prime minister’s office since 2016. Muhandis — sanctioned by the United States as a Specially Designated Global Terrorist (SDGT) — relies on the Iraqi state to protect him and his organization from international interference.

Post-ISIS fallout for the Iran-backed coalition

Although the two sides fought against a common enemy in the Islamic State, Washington has since begun to sanction several leaders of the PMF, particularly those who share strong relations with the Iranian Revolutionary Guard Corps’ Quds Force. The United States is concerned that the weapons caches and military capabilities of certain pro-Iranian PMF groups may threaten it or its allies in the region at a later date.

The maximum-pressure campaign against Iran and its regional allies, including the PMF, is a significant leap in Washington’s pressure on Iraq. The U.S. leadership has lost trust in the formal Iraqi leadership’s ability to rein in or control the paramilitary groups. After the previous civil war (2006-2007), the U.S. government and Gen. David Petraeus played a significant role in working with Maliki to fight against the Mahdi Army, which at the time had become a strong paramilitary force. At that point, the Americans had significant leverage over Iraq’s formal state bureaucracy. This time, again after a civil war, the PMF has become a strong paramilitary force, but the Americans have lost their leverage and trust in the prime minister’s ability to combat paramilitary groups in Iraq. As such, they have decided to take matters into their own hands by ramping up pressure.

What’s next for the PMF?

The U.S. maximum-pressure campaign and the recent airstrikes challenge the formal-de facto status-quo that has governed the relationship between the PMF and the state. Until now, Muhandis left official foreign affairs to the formal bureaucracy, which would protect him from international enemies. Sensing that the formal leadership was unable to live up to its end of the deal after increased American pressure, Muhandis decided to directly address the West and speak on behalf of the formal bureaucracy in his letter.

After the fight against the Islamic State, Muhandis faces internal challenges in his pursuit to consolidate the PMF. Several groups have refused to give up power, leading to infighting, and many Iraqi citizens who once supported the PMF are now calling for its disbandment. In 2018, for example, residents of Basra — where an estimated one-third of the PMF fighters are from — demonstrated against the main PMF groups. In response, PMF leadership is using U.S. or regional antagonisms to construct an external threat to try to maintain their constituencies throughout Iraq.

More critically for the state, the maximum-pressure policy reveals a change in the dynamic between de facto and formal military leaders in Iraq. Until now, the de facto PMF leadership has been satisfied with its hybrid security, political, economic and social role on the ground, leaving formal politics to the formal leadership. The latter, however, may be unable to protect the PMF from Western aggression. If so, Muhandis and his colleagues may reconsider their understanding with the formal state leadership.

Renad Mansour is a research fellow with the Middle East and North Africa Program at Chatham House and co-author of “Between Chaos and Order: A New Approach to Stalled State Transformations in Iraq and Yemen” (Chatham House, September 2019).