Bomb components from Iran used to make deadly improvised explosives devices (IEDs) seized by American forces in Iraq in 2007.


Since the fall of Saddam Hussein’s regime in 2003, Iran has waged proxy warfare in Iraq as it has sought to significantly increase its influence and oust America’s military presence from the country. Iran’s quest for primacy in Iraq is an important component of its hegemonic regional project to export the Islamic Revolution throughout the Middle East. Iraq is also an important link in Iran’s efforts to establish a “Shi’a crescent” that functionally serves as a land bridge linking Tehran to Lebanon and the Mediterranean, enabling Iran to more efficiently and lethally arm Hezbollah and its other regional proxies.  

Sharing a 900 mile border with Iran, Iraq under the Sunni Baathist regime of Saddam Hussein was Iran’s primary geostrategic adversary. Iran viewed the U.S. invasion in 2003 as an opportunity to transform its foe into a client state and base from which to direct revolutionary activities around the Middle East. To that end, Iran has sought to cultivate loyalty among Iraq’s Shi’a majority population, seeking to leverage shared sectarian identity to justify its meddling and anchor its influence in Iraq.  

In order to bolster its influence, Iran aims to keep Iraq weak and dependent on Tehran for its security. Iran has stood up and controls a vast network of Shi’a militant groups in Iraq, and uses these proxies to “stoke sectarian tensions and to foment political violence… thereby ensuring for itself a role as mediator in Iraq.” This “two-faced” strategy has enabled Iran to establish itself as the “key power broker” in Iraq.

Support for Shi’a Militias

Since the 2003 onset of the Iraq War, Iran supported, trained, and funded Shi’a militias and Shi’a insurgents in order to “work toward a humiliating defeat for the United States.” Until his death in a US drone strike targeting his convoy as it left Baghdad’s international airport on January 3, 2020, Islamic Revolutionary Guard Corps (IRGC) Quds Force Commander Qassem Soleimani served as Iran’s primary agent of influence in Iraq, overseeing the training and arming and coordinating the battlefield activities of various Iran-backed Shi’a militias operating in Iraq. Through a combination of military aid, cash, favors, bribes, and intimidation, Soleimani came to wield tremendous personal influence over the country’s Shi’a militias and political parties. Politicians were effectively held hostage to Soleimani’s demands, as he could call on the militias under his command to make trouble if they tried to cross him.

Iran supplied these groups with weapons such as IEDs, which were “top killer of US troops” in Iraq. In order to move these weapons into Iraq, Iran controlled a number of arms smuggling rings. By 2006 the Quds Force, the extraterritorial military arm of the IRGC, had developed “a widespread network for transferring and distributing arms from Iran into Iraq through the Ilam region in western Iran.”

Iran’s imprimatur over the militias was most vividly borne out with the evolution from primitive Improvised Explosive Device (IED) attacks on US service members to more lethal explosively formed projectile (EFP) attacks, whose sophistication US military officials insist point to Iranian origins. In total, the US Pentagon found that Iran-backed militias were responsible for 603 US servicemember deaths between 2003-2011, accounting for roughly one in six US casualties during that period. The sectarian violence Iran helped unleash also claimed the lives of tens of thousands of Iraqi civilians in the years following the invasion.

According to the US State Department Country Reports on Terrorism 2019, Iran-backed Shia militia groups are believed to be responsible for more than a dozen rocket or indirect fire attacks targeting US or Coalition targets in Iraq in 2019, including the December 27 attack in which KH launched more than 30 rockets at an Iraqi base hosting US forces in Kirkuk, killing one American contractor and wounding several American and Iraqi service members.

On March 5, 2019, the US Department of State designated Harakat Hezbollah al-Nujaba (HHN), an Iranian proxy group established in 2013 with direct support from the IRGC. HHN is an Iran-backed Iraqi militia funded by but not under the control of the Iraqi government. HHN has openly pledged its loyalties to Iran and Iranian Supreme Leader Ayatollah Khamenei. The group’s founder, Akram al-Kaabi, was one of the cofounders of the IRGC-backed militia Asaib Ahl al-Haq (AAH) and many of the group’s fighters are former members of AAH and Kataib Hezbollah (KH). Kaabi openly admitted in 2015 that “technical and logistical support comes from the [Iranian] Islamic Republic.” The group has been active in Syria as well, and is alleged by Iraqi officials to be “helping Tehran create a supply route through Iraq to Damascus.”

On January 3, 2020, the US Department of State designated Asa’ib Ahl al Haq (AAH) under Section 219 of the Immigration and Nationality Act, and designated its leaders Qais and Laith al-Khazali as Specially Designated Global Terrorists under Executive Order 13224. In a statement, Secretary of State Mike Pompeo alleged, “AAH and its leaders are violent proxies of the Islamic Republic of Iran. Acting on behalf of their masters in Tehran, they use violence and terror to further the Iranian regime’s efforts to undermine Iraqi sovereignty.”

Fight against ISIS

Iran’s hostile takeover of Iraq stoked sectarian backlash, catalyzing the rise and potency of the Islamic State (ISIS). In 2014, at the apex of ISIS’s power, the group took over Mosul with little resistance from Iraqi government forces and began advancing toward the outskirts of Baghdad. At the time, Iran’s primary focus had shifted to Syria, and Iran had diverted much of its Shi’a militia personnel to the effort to rescue the Assad regime. When the ISIS situation demanded action, Soleimani ordered the Iraqi militias to cross back over Syria's border to rescue Iraq.

Iran has used the war against ISIS as a pretext to embed IRGC officials in Iraq and increase support for Shi’a militant groups loyal to Ayatollah Khamenei. In conjunction with the Iraqi government, Soleimani helped stand up the Popular Mobilization Forces (PMF), an umbrella organization of predominantly Shi’a militia groups that coordinated with Iraq’s central government in the fight against ISIS. While not all the PMF forces are aligned with Iran, about 50 Shi'a militia groups are backed by Iran including some of the largest, best-funded, and most heavily armed groups. The creation of the PMF command structure and its integration with the Iraqi central government led to unprecedented coordination among the Iran-backed Shi’a militias and has helped entrench Iranian control over Iraqi affairs.

Reports on the number of IRGC soldiers killed fighting in Iraq further demonstrate Iran’s intense interventions in the area. Iran has supplied Iraq with $10 billion worth of weaponry, likely including T-72S tanks, Safir jeeps, and Sayyad sniper rifles.

As a result of these interventions against ISIS, Iranian influence in Iraq reached an “unprecedented level.” According to Ali Younusi, an adviser to Iranian Supreme Leader Khamenei, “Iran is an empire once again at last, and its capital is Baghdad.” A member of the Iranian parliament made a similar claim, declaring that Baghdad has “fallen into Iran’s hands and belongs to the Iranian Islamic Revolution.” Soleimani also echoed these sentiments boasting, “We are witnessing the export of the Islamic Revolution throughout the region… From Bahrain and Iraq to Syria, Yemen and North Africa.”

The Iran-backed Shi’a militias engaged in systemic human rights abuses and brutality that rivaled ISIS as they cleared out ISIS territory. Iraqi Shi’a militias were alleged to have engaged in extrajudicial assassinations, summary executions, kidnappings, and torture of both combatants and civilians, including children. 

Due to the armed strength and brutality of the Shia militias within the PMF, their power has come to eclipse that of the central government, leading Iraqi officials to either surrender to and appease the PMF, or face reprisals. Iraq’s former prime minister, Haider al-Abadi, praised Iran at Davos in 2015 for springing to Iraq’s defense and even singled out Qassem Soleimani as an ally in the fight against ISIS. There are reportedly around 80,000 to 100,000 Iran-aligned Shia fighters inside Iraq today, and the government has little recourse to bring the Iran-backed militias, which desire to retain their independence, under its command. It’s this Shi’a militia infrastructure that provides Iran a vehicle to threaten US interests in the aftermath of the US withdrawal from the Iran nuclear deal. At Tehran’s behest, these militias have been operationalized to push back against the Trump administration’s “maximum pressure” campaign,  attacking US personnel and energy interests in Iraq. Reuters reported in August 2018 that Iran had recently transferred short-range ballistic missiles to its allies in Iraq. These kinds of missiles include the Zelzal, Fateh-110, and Zolfaqar, which can all travel from 200-700 km. This range places US allies—Israel and Saudi Arabia—within reach. Indeed, the US government was forced to shutter its consulate in Basra in September 2018 after Iranian-supported militias fired rockets at the compound.

Iran’s transfer of ballistic missiles to its proxies, the establishment of weapons depots in Iraq, and transformation of the country into a transshipment route for arms to the Assad regime and Hezbollah have further undermined Iraqi sovereignty, imperiling the central government’s monopoly on the use of force These provocations have invited reprisals from Israel, highlighting Iran’s willingness to subvert Iraq’s security for its own nefarious ends.

Political and Economic Influence

The kinetic power of these militias buys influence in Iraqi politics. The Iranian embassy in Baghdad is a hub of the mullahs’ machinations in Iraq—specifically because Iran’s Ambassador to Iraq Iraj Masjedi is himself a former general in the Quds Force and has served as a top advisor to Quds Force Commander Qassem Soleimani. It’s from this platform that Tehran wields powerful influence over the direction of Iraqi politics.

After the May 2018 parliamentary elections, which saw the Iran-backed Fatah alliance finish second in the vote tally, Iran and its allies were intimately involved in the negotiations over government formation. For example, Muqtada al-Sadr, whose nationalist Sairoon coalition came in first in the elections, traveled to Lebanon in September 2018 where he was hosted by Hezbollah’s Secretary-General Hassan Nasrallah and Qassem Soleimani to forge a consensus on who would become the next prime minister of Iraq. The trio settled on Adel Abdul-Mahdi, a former oil minister and vice president of Iraq. According to leaked Iranian intelligence cables obtained by the Intercept, Abdul-Mahdi worked closely with Iran dating back to his time in exile as an opponent of Saddam Hussein’s regime and as oil minister, had a “special relationship with the IRI.” Abdul-Mahdi was hailed as a compromise candidate palatable to the US and Iraq, but his selection highlighted that no Iraqi prime minister could assume power without Iran’s backing. While Mahdi has been described as an independent-minded technocrat, after taking office, he granted Iran preferential access to his inner circle. In October 2018, only 24 hours after announcing he would not meet with delegations from foreign embassies as his cabinet was in the process of being formed—out of fear of an appearance of impropriety in the decision-making process—he hosted the Iranian Ambassador Iraj Masjedi for a discussion.

Outside the political realm, Iran also maintains economic leverage over Iraq. According to Ambassador Masjedi, Iran’s second-largest export market is Iraq, with bilateral trade set to reach $8.5 billion in 2018, with Iran hoping to increase the trade volume to $22 billion annually. Indeed, the United States has had to continually grant Iraq a periodic waiver from US sanctions that the US government re-imposed on Iran following its withdrawal from the Iran nuclear deal allowing it to import gas and electricity from Iran.

An additional node for Iranian influence is its development of Shi’a shrines in Iraq. According to a December 2020 Reuters report, Iran has poured hundreds of millions of dollars into the construction and upgrading of religious sites in Iraq. Construction companies linked to charitable foundations owned by the IRGC are behind the construction bonanza. The primary organization overseeing the development of shrines is called the Holy Shrines Reconstruction Headquarters. It was set up by Supreme Leader Khamenei and is run by IRGC appointees. Such arrangements are part of Khamenei’s efforts to establish patronage links to the IRGC, enriching Guardsmen and ensuring their fealty to the Supreme Leader. In March 2020, the organization was sanctioned by the US Treasury Department which alleged it was controlled by the Quds Force and served as a front for funneling lethal aid to Iran-backed proxies, intelligence activities, and money laundering.

Millions of religious pilgrims pass through Iraq’s shrines each year, giving Iran the opportunity to proselytize its Khomeinist ideology. Iran is seeking in the long term to influence the selection of a successor to Ayatollah Ali Al-Sistani, Iraq’s most powerful Shi’a cleric and a rival source of emulation for Shi’a Muslims to Khamenei. A successor more favorable to its state ideology in Najaf would cement Iranian cultural and political influence in Iraq in the long term. Thus, even at a time when it faces massive economic pressures due to sanctions, Iran has seen fit to divert massive amounts of funds to shrine development in Iraq.  

In moves showcasing Iranian influence in Iraq, the US Treasury Department sanctioned Iran’s Ambassador to Iraq Iraj Masjedi as a Specially-Designated Global Terrorist and later the Chairman of the Popular Mobilization Committee and Iraq’s former National Security Advisor Falih al-Fayyadh under the Global Magnitsky Act for human rights abuses. The designation of Masjedi was significant, especially for shining a light on Iran’s embedding of Quds Force generals in Iran’s diplomatic postings. The sanction on al-Fayyadh was also important given his history and the fact that al-Fayyadh had visited Washington in the past in order to discuss Iraqi stability. But al-Fayyadh has long been close with Iran, recently traveling to Tehran for the commemoration of the first anniversary of Soleimani’s death.


Iran’s control over Shi’a militias has made it the dominant military, political, and diplomatic power broker in Iraq, but its quest for domination and subversion of Iraqi interests to its own has weakened Iraq’s central government and impeded its ability to provide for the welfare of its citizens. Meanwhile, Iran’s project to cultivate patronage links among Iraq’s Shi’a population through its militias, which provide social services in addition to security, has failed to take root, as widespread unemployment and economic privation remain the norm. Iran’s revolutionary bravado has proved insufficient to override its ineptitude at basic governance, and the result has been a backlash against Tehran that has metastasized into a mass protest movement ongoing since October 2019.   

The protests gripping Iraq have witnessed tens of thousands of demonstrators taking to the streets to vent their dissatisfaction with the government of Prime Minister Adil Abdul-Mahdi, an out-of-touch class of political elites, and Iran-backed militias. Too often, these forces have placed Iran’s interests over the public good, for instance steering Iraq’s oil resources to benefit Tehran while Iraq’s own citizens lack healthcare, jobs, educational opportunity, consistent electricity, and clean drinking water. Notably, the Iraqi protestors are almost exclusively Shi’a, showing that Iran’s political and military maneuvering has failed to translate to winning over the hearts and minds of the core constituency it needs to continue projecting influence in Iraq. Calls for more inclusive governance were high among the protestors’ demands, highlighting the unpopularity of Iran’s explicitly sectarian approach.

Iran has responded to the Iraqi protest movement with repression, dispatching former Quds Force commander Qassem Soleimani to Baghdad immediately after protests began to advise Iraqi politicians and security officials on his best practices for quelling unrest. According to Iraqi security officials present at the meeting, Soleimani, who chaired the meeting in place of Prime Minister Abdul-Mahdi, told those present, “We in Iran know how to deal with protests. This happened in Iran and we got it under control.”

While directing the suppression of the Iraqi protests, Soleimani also ordered the Iran-backed militias under his control to undertake a concerted campaign of rocket attacks targeting US military targets in the country. According to a US military official, forensic analysis of the rockets and launchers used during the spate of at least ten attacks indicated the involvement of Shia militias, most notably Asaib Ahl al-Haq and Katai’b Hezbollah (KH). On December 27, 2019, more than 30 missiles were fired at an Iraqi military base near Kirkuk, killing a US contractor and wounding four US troops as well as two members of the Iraqi security forces. The US accused KH of being responsible for the attack, and retaliated by launching strikes against 5 KH targets in Iraq and Syria including weapons depots and command and control centers. The US strikes reportedly killed at least 25 KH militants.

On December 31, 2019, protesters, including members and supporters of KH, attempted to storm the US Embassy in Baghdad. Demonstrators threw stones and torched a security post, prompting embassy guards to respond with stun grenades and tear gas. The militia supporters withdrew from the embassy after prominent commanders reportedly spoke to them. On January 1, 2020, following orders from Mohammed Mohyee, KH’s political spokesman, thousands of protestors dispersed from the American Embassy in Baghdad. 

In the early morning hours of January 3, 2020, President Trump greenlit a drone strike targeting Soleimani’s convoy shortly after his arrival in Baghdad. The head of KH, Abu Mahdi al-Mohandes, who also served as deputy head of the PMF, was killed in the strike as well. Despite their deaths, the powerful network of Iran-backed Shi’a militias will continue to remain a fixture in Iraq, upholding Iran’s influence increasingly through repression.

Iran’s leadership has vowed devastating reprisals against the US for the operation to kill Soleimani, and they followed up on this threat by firing a salvo of over a dozen ballistic missiles at two Iraqi air bases housing US troops in the early morning hours of January 8, wounding 11 US soldiers.

Following the attack, a period of calm prevailed, although Iran signaled that it is likely to strike US interests again at a future time of its choosing. Iran’s Supreme Leader, Ayatollah Ali Khamenei, intoned that while the ballistic missile attack represented a “slap on the face” for the US, “military action like this (ballistic missile) attack is not sufficient,” vowing to refuse to enter negotiations and to continue to confront the US until its influence is expelled from the region. In the intervening period, Iran’s leaders maintained a steady drumbeat of threatening rhetoric aimed at the US, with Soleimani’s successor, Esmail Qaani, for instance vowing to “hit his enemy in a manly fashion.” 

On March 11, 2020, the calm was broken as what were presumed to be Iran-backed militia forces launched a Katyusha rocket salvo targeting US and coalition troops stationed at Camp Taji, 17 miles north of Baghdad. Two US soldiers and one British soldier were killed in the attack, and an additional twelve soldiers were injured. The attack crossed a US red line as it killed US servicemembers, once again raising US-Iran tensions. The attack coincided with what would have been Qassem Soleimani’s 63rd birthday, but it is unclear whether the attack was ordered directly by Iran, as the assassination of Soleimani likely has affected command and control between Tehran and its proxies in Iraq. Following the attack, airstrikes were carried out around the Abukamal Syria-Iraq border crossing, where Iran-backed militias are known to have a strong presence. The US has not claimed credit for the airstrikes at this time.  

In the aftermath of Soleimani’s death, Iraq’s protest movement has continued to gain steam, with demonstrators venting their frustration that Iran’s disregard for Iraqi sovereignty has increasingly ensnarled their country as a staging ground for proxy warfare between Iran and the US Soleimani’s successor as Quds Force commander, Brigadier General Esmail Qaani has struggled to wield control over Iraq in the same manner as Soleimani. Qaani, who previously focused primarily on Afghanistan, Pakistan, and Central Asia lacks the relationships with Iraqi political and militia leaders of all stripes that Soleimani, who was universally feared if not respected, had cultivated.

As such, Hezbollah has had to fill the void created by Soleimani’s death, taking over coordination of militia operations in Iraq. In April 2020, the US State Department announced a $10 million reward for information on Hezbollah operative Sheikh Mohammad al-Kawtharani, alleging he had “taken over some of the political coordination of Iran-aligned paramilitary groups” that had previously been Soleimani’s purview. Tehran’s command and control of the various militia groups it backs have been degraded as a result. Its ability to dictate outcomes in Iraq’s political affairs has been set back as well.

In late March 2020, Qaani made his first visit to Baghdad seeking to establish continuity with his predecessor and reassert the Quds Force’s influence. His visit was widely seen as a failure. He sought to unite Iraqi militia and political factions in supporting an anti-American, pro-Iranian prime minister, but Iraq ultimately selected former intelligence chief Mustafa al-Kadhimi, who is viewed as supportive of US interests. Qaani was snubbed on his visit by Moqtada al-Sadr, who refused to meet with him. Such a snub would have been unheard of for Soleimani, and demonstrated that Tehran no longer commanded the fear and respect it previously engendered.

In the final months of the Trump administration, Iran has sought to restrain the Iraqi militias it backs from attacking the US, seeking to wait out the clock and avoid any escalations. In November 2020, Qaani reportedly visited Beirut to meet with Hezbollah leader Hassan Nasrallah to secure his assistance in reining in Iran-backed Iraqi militias. Qaani then went to Baghdad to meet the Prime Minister and several militia leaders to urge restraint. While some militias have followed Tehran’s orders, most notably Kataib Hezbollah, others have openly defied Tehran. Asaib Ahl al-Haq leader Qais al-Khazali gave a TV interview after Qaani’s visit in which he vowed to continue confronting the US, declaring, “The Americans occupy our country, not yours. We will not listen to you anymore because our motives are 100 percent nationalist. The truce with the Americans has ended due to its conditions not being met.”

Since Qaani’s visit, Iraqi militias have continued to carry out attacks on US interests. On November 17, 2020, militants targeted the US embassy with a volley of rockets. On December 10, two convoys carrying logistical equipment to the US-led coalition were attacked by roadside bombs. On December 20, the embassy was targeted with another salvo of 21 rockets, in the largest attack on the Green Zone in a decade. The repeat violations of the tenuous cease-fire have been condemned by Kataib Hezbollah and other factions close to Iran, but show that the Iran-backed militias remain divided in their approach to confronting the US and that under Qaani, the Quds Force can no longer enforce discipline among their ranks. Qaani made another visit to Iraq in December, with Al-Alam news network claiming it was unrelated to the December 20 attack.

Iranian-backed militias have continued to launch attacks against the US military presence in Iraq since Joseph Biden assumed the US presidency, presumably as part of Tehran’s strategy to increase its leverage and compel the US to make up-front concessions ahead of the resumption of nuclear negotiations.

On February 15, 2021, suspected Iran-backed militants launched a salvo of 14 rockets targeting a heavily fortified US military compound in Erbil, in Iraqi Kurdistan, with three rockets hitting the base. A civilian contractor to the US military with Filipino nationality was killed, and an Iraqi civilian died a week later due to injuries sustained in the attack. At least eight others were injured in the attacks, including a US soldier and five military contractors. On March 3, Kurdish counterterror authorities released a confession from one of the perpetrators of the attack who said he carried out the attack along with other individuals who belonged to the Iran-backed militia Kataib Sayyid al-Shuhada (KSS), which is part of the PMF. The suspected attacker further claimed to have used Iranian-made rockets in the attack. KSS is believed to be an offshoot with operational links to the Badr Organization. The group’s propaganda frequently features images of Supreme Leader Khamenei, indicating the group’s fealty to the Iranian regime.  

Several days after the Erbil attack, militants fired rockets at the Balad air base, where a US defense firm services Iraq’s fighter jets, and at Baghdad’s Green Zone compound, where the US Embassy is located. The US responded to the uptick in violent attacks by launching airstrikes targeting Iran-backed militia forces on the Syrian side of the Iraq-Syria Abukamal border crossing on February 25, 2021, a choice calibrated to respond to and deter further Iranian aggression while not creating political headaches for the Iraqi central government. According to Pentagon spokesman John Kirby, the facilities targeted were used by Kataib Hezbollah and Kataib Sayyid al-Shuhada. On March 3, 2021, US forces were targeted again by a rocket barrage that US defense officials believe was launched by Kataib Hezbollah or an affiliated Iran-backed militia. A US contractor suffered a fatal cardiac episode during the attack.

Iraq’s continuing political instability and protests, as well as the sporadic hostilities between Iran-backed proxy forces and the US, pose formidable challenges to those wishing to restore sovereignty and democracy to Iraq, a situation which Iran will continue to exploit. While Soleimani’s death posed a setback to Iran’s ability to project influence in Iraq, it still wields considerable power over the key militias in the PMF and can marshal groups to confront the US at the time of its choosing.

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