- Iran-backed militias within Iraq’s Popular Mobilization Forces (PMF) have acquired short-range ballistic missiles from Tehran, supplementing their existing arsenal of unguided rockets.
- These militias’ small, harassing rocket attacks targeting U.S. facilities in Iraq have already disrupted American diplomatic and business activities in the country.
- Israeli airstrikes on PMF missile depots have killed and injured dozens of Iraqis, straining relations among the United States, Iraq, and Israel.
- Further Iranian missile proliferation in Iraq could increase the number of potential rocket launch sites, impede the attribution of Iranian missile attacks, and locate launch sites closer to U.S. and allied forces in the region.
In discussions of Iran’s regional missile proliferation, Lebanese Hezbollah and Yemen’s Houthi rebels tend to dominate the conversation. This focus is for good reason: Hezbollah today possesses an estimated 130,000 rockets and short-range missiles, and the Houthis have fired over 250 projectiles into Saudi Arabia since 2015.1 Yet Iran’s strategy of arming proxies with rockets to harass, distract, and deter its regional adversaries has expanded to include factions of a third group. Collectively known as the Popular Mobilization Forces (PMF) in Iraq, these militias have taken on increasing importance.
The PMF is a semi-autonomous umbrella group composed of an estimated 75,000-145,000 fighters, split among 50-plus militias.2 It was formally established in 2014 to help Iraq’s armed forces defeat ISIS. Given its complex bureaucracy and history, the organization as a whole should not be considered an Iranian proxy. Each group varies in its politics and interests, with only some loyal to Tehran.3 However, those groups and PMF leaders that do maintain strong ties to Tehran have steadily risen in size and stature. This report designates these factions of the PMF as “Iran-backed Groups,” or “IBGs,” to focus the scope of its analysis.4
Table 1: Prominent Iran-backed Groups in the PMF
Iran has provided training and lethal aid to IBGs since the 1980s.5 Tehran’s provision of sophisticated missiles to these militias, however, is a more recent and growing concern for the United States. An August 2018 report revealed that Iran had transferred a few dozen short-range ballistic missiles to the IBGs. These shipments included the Zelzal (150-250 km), Fateh-110 (200-300 km), and Zolfaghar (700 km) missiles, complementing the militias’ existing arsenal of unguided 107-mm and 122-mm rockets.6 These transfers follow and are likely meant to compensate for Iran’s failed efforts to establish forward-deployed bases in Syria.7 By early May 2019, Secretary of State Mike Pompeo made an unannounced trip to Iraq to discuss the danger of Iranian missile transfers.8 Both Congress and the Trump administration have also issued repeated warnings that the United States would consider any attack by Iranian proxies as an attack by Iran.9 IBG missile acquisitions have also prompted Israel to launch at least seven airstrikes so far on PMF missile depots in Iraq in 2019, expanding upon Israeli policy of targeting Iranian missile bases in Syria.10 Nevertheless, recent news reports have highlighted the prospect of additional Iranian missile transfers into Iraq.11
Threats and Implications
The United States faces three principal challenges regarding IBG rockets. The first is IBG use of projectiles to harass U.S. and Iraqi facilities, disrupting American diplomatic and business activities in Iraq. The second includes the political risks of preemptive or preventative action—namely, Israeli airstrikes on Iraqi weapons depots. While effective in the short-term, these attacks have killed and injured dozens of Iraqis and raised public outcry over Iraq’s national sovereignty, straining relations among the United States, Iraq, and Israel. A third challenge encompasses the many ways in which Iran could use and benefit from a proxy rocket force in Iraq. Through shipment of increasingly sophisticated weapons to IBGs, Tehran could increase the number of potential rocket launch sites, further impede the attribution of Iranian missile and drone attacks and locate launch sites closer to U.S. and allied forces in the region.
1. Harassment of U.S. and Iraqi Facilities
IBGs in Iraq possess a sizeable stockpile of unguided 107-mm and 122-mm rockets, manufactured both locally and in Iran.12 Since September 2018, IBG militants have fired over 30 rockets at U.S. facilities in Iraq, including the U.S. embassy in Baghdad, consulate in Basra, and military training facilities in Taji, Mosul, and Nineveh.13 They have also targeted an Iraqi oil field in Basra which contained American personnel. Based on their timing—often following statements or actions considered harmful to Iranian/IBG interests—and inaccuracy, these attacks are primarily conducted to signal frustration with U.S. or Iraqi policy. Nevertheless, they have still resulted in casualties. An October 30 salvo killed one Iraqi soldier working at a Green Zone checkpoint in Baghdad, and an earlier June 19 attack injured three Iraqi civilians.14
U.S. officials say these attacks are a serious threat to its personnel and have taken action in response. The State Department closed its consulate in Basra just hours after a September 2018 rocket attack and has kept it vacant since. In a written statement, Secretary Pompeo explained the closure followed “repeated incidents of indirect fire from elements of those militias.”15 Following new intelligence related to Iranian missile deployments, the State Department withdrew all nonessential personnel from its embassy in Baghdad and consulate in Erbil in May 2019.16
These closures have had significant diplomatic consequences by restricting the space and workforce for diplomats operating in-country. As of July 2019, the Baghdad embassy reportedly had less than 15 officials working on core diplomatic functions following the partial evacuation in May.17 As one senior State Department official said, “We took a powerful functioning embassy that was keeping Iranian influence at bay and created space for the U.S. to exert influence, and we gutted it.”18 These closures could also increase the rocket threat to remaining U.S. personnel, as Iran finds it can limit U.S. diplomatic capability through small-scale attacks.
Such rocket attacks have also harmed U.S. private-sector investment opportunities in Iraq. Exxon Mobil presents one clear case study. Operating in southern Iraq since January 2010, Exxon has invested significantly in Iraq and aims to expand its activities through a potential $53 billion extraction deal. Recent IBG attacks, however, have put these activities at risk. In May 2019, Exxon evacuated 80 personnel amid security concerns relating to Iran-backed militias.19 On June 19, an IBG launched a Katyusha rocket attack on Exxon’s Basra facility, injuring three local Iraqi workers and forcing Exxon to evacuate 21 foreign workers.20 These disruptions have since generated concern among other potential U.S. investors in Iraq. After the June 19 attack on Exxon personnel, one news report suggested that companies were becoming “more cautious about moving forward.”21
2. Escalation Risks
Despite attention from U.S. and Iraqi leadership, Iranian short-range ballistic missiles have still found their way into Iraq, pushing Israel to act. Between July and September 2019, Israel conducted at least seven airstrikes on PMF missile and ammunition depots in western and central Iraq. While the Israeli Ministry of Defence has not publicly confirmed these strikes, U.S. and Iraqi officials have affirmed that Israel is behind the attacks.22
Table 2: Reported Israeli Strikes on PMF Bases
While successful in denying Iran its desired forward-deployed missile bases, Israel’s airstrikes have generated significant political blowback. Following an Israeli airstrike on August 12, the Iraqi government ordered a ban on all military flights in the country unless authorized by the Iraqi Defense Ministry, a policy that could slow U.S. response times to emergency requests.23 Unilateral Israeli action could have further ramifications for the United States. Even if the United States is uninvolved, as officials claim, various Iraqi and PMF officials say they hold the United States responsible for strikes.24 Consequences could get worse yet: as one senior American official warned, too many strikes could get the U.S. military removed from Iraq.25 While Iraq’s current, U.S.-friendly administration is unlikely to take such drastic measures, further attacks could push Iraqi voters to elect more pro-Iran candidates in the future.
Even less acute forms of blowback are problematic. Repeated Israeli airstrikes have already renewed Iraq’s internal debate on procuring non-American air defenses, believed necessary for Baghdad to “impose sovereignty over its airspace.”26 Systems like Russia’s S-300 or the Iran’s Bavar-373 may be more capable of attacking Israeli UAVs than U.S. air defenses, which probably identify these aircraft as friendly units. Acquiring such systems, however, could increase the risk of providing U.S. adversaries with intelligence on U.S. aircraft and military operations. These foreign air defenses would track U.S. and allied aircraft operating in Iraq, and the personnel managing these systems could then forward these records to their countries of origin.27 The PMF have taken at least one concrete step in this direction: on September 5, PMF Deputy Chief Abu Mahdi al-Muhandis ordered the creation of a PMF air force.28 The United States has previously sanctioned its appointed lead, Salah Mahdi Hantoush, for his involvement in terrorist activity.29
3. Another Iranian Proxy
Iran’s proxy forces comprise an essential element of its military and deterrence strategy.30 In their operations against Israel and Saudi Arabia, Hezbollah and Houthi fighters have repeatedly demonstrated their utility for Tehran in harassing, distracting, and deterring its competitors. Should Iran develop the IBGs to a similar degree (if it has not already), the militias could serve Tehran’s interests in several ways.
First, the growing list of regional actors with Iranian missile technology could make attack attribution more difficult, supporting Iranian efforts in maintaining plausible deniability. Iran seeks plausible deniability in its attacks to raise uncertainty in U.S. and allied assessments, making it more difficult for policymakers to legitimatize a military response.31 Plausible deniability also helps shield Tehran from international criticism regarding its morally dubious activities.32 Iran has used the Houthis several times for these purposes. On June 13, for example, Iran blamed the Houthis for attacks on two oil tankers transiting the Gulf of Oman. This explanation seemed plausible, given previous Houthi attacks on other ships. Footage captured by an American MQ-9 drone, however, later showed IRGC sailors removing an unexploded mine from one of the ships, thus strongly implicating Iranian involvement.33
A new proxy in Iraq would also provide Iran with a greater number of launch points for various air threats, including ballistic or cruise missiles, artillery rockets, or armed-UAVs. This increase in potential attack vectors would also complicate U.S. and allied missile defense. Armed with 120-degree sectored Patriot radars, for example, Saudi Arabia struggles to comprehensively cover potential launch points in Yemen, Iran, and Iraq at once. Such limitations may explain why Saudi air defenses failed to detect a September 14 attack on refineries at Abqaiq and Khurais coming from the north, during which Saudi radars were reportedly focused on air and missile threats coming from Yemen to the south.34 Similarly, a May 14 drone attack on a major Saudi oil pipeline caught Saudi air defenders unaware. While Houthi rebels initially claimed responsibility, U.S. officials later said the attack originated from Iraq, likely launched by Kata’ib Hezbollah.35
Iran’s missile proliferation would also complicate “Scud hunting” in a wartime scenario. In a regional conflict, the United States and its partners would have to devote more intelligence, reconnaissance, and surveillance (ISR) and strike assets to cover IBG operating areas to destroy missiles before they launch. IBG rocket launch sites are also located close to U.S. military facilities in Iraq, thus enabling the militias to expand the conflict west through mortar, rocket, or missile fires.36
Managing the IBG Threat
The emergence of another Iranian proxy armed with rockets and missiles is a significant development in the Middle East. Left unsettled, it risks wider military escalation, worsened U.S.-Iraqi relations, and greater Iranian power projection across the region.
Direct counterproliferation efforts have yielded little return thus far. U.S. policymakers have repeatedly communicated to Iraqi leadership on the need to engage with these issues, but Iraqi policymakers have failed to make substantial progress.37 Iraqis will also not accept continued Israeli airstrikes over their territory as a new status quo. While U.S. dialogue with Iran could potentially reduce the threat, the benefits Tehran stands to gain from an Iraqi proxy force make Iranian concessions unlikely.
The IBG threat will remain, pending major political shifts in Tehran or Baghdad. Nevertheless, in order to manage and minimize this threat, Washington may need to expand its counterproliferation strategy—more so politically than militarily. This primarily means increasing resources dedicated to countering Iranian influence in Iraq, but also to weakening, delegitimizing, and regulating IBGs.
Table 3: Possible Approaches to Counter Iran-Backed Groups
Analysts have posited various political, diplomatic, military, and economic strategies in support of these missions (Table 3). Some options are attractive, requiring minimal U.S. resources and inviting little operational risk. On the political-diplomatic front, this includes strengthening the U.S. diplomatic corps in Iraq, continuing to engage in high-level dialogue with Iraqi and Israeli leadership, and (perhaps indirectly) naming and shaming IBGs for prioritizing Iranian interests over those of Iraq. Regarding military engagement, continued U.S. support for Iraq’s national security services is essential. Encouraging those forces to oversee and regulate PMF-controlled infrastructure may also help minimize potential proliferation nodes. And on the economic side, U.S. support for non-Iranian trade partners for Iraq would serve broad interests in limiting Iranian influence.
To be sure, these policies are long-term approaches that are likely either ongoing or have already been attempted. There are other more risk-tolerant strategies to immediately push back on IBGs and Iranian influence, but these face several challenges. Some options, like conditioning U.S. aid on PMF reform or incentivizing PMF retirement, are politically costly for U.S. and Iraqi policymakers. Others, such as direct attacks on IBGs or their IRGC partners, may incite retaliation. U.S. and Iraqi officials also cannot implement these policies in a cookie-cutter fashion given differences in the militias’ politics, interests, and likely reactions.38 Moreover, officials must always consider potential Iranian responses.
The complexity presented here is obvious, but so too is the need for engagement. U.S. officials should push forward on some mix of these and other counter-IBG policies, following careful analysis on potential costs and benefits. Even if the IBG threat cannot be removed completely, the possibility that it can be managed in a way that satisfies U.S., Iraqi, Israeli, and perhaps even Iranian interests makes such efforts worthwhile.
Shaan Shaikh is a program manager and research associate with the Missile Defense Project at the Center for International and Strategic Studies in Washington, D.C.
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