The battle for Mosul is finally underway. The fight to dislodge the Islamic State (ISIS) from Iraq’s second largest city, which it has occupied since June 2014, promises to be a bloody slog. A battlefield victory could take weeks or even months.

In addition to the challenges of taking the city, the sheer array of actors involved in the Mosul drama could lead to serious complications once ISIS is driven out. The United States is backing a coalition that includes Iraqi military forces and Sunni tribal militias. Kurdish Peshmerga and largely Shiite militia groups are also involved, but they are confined to liberating villages and towns outside the city. The plan is to whittle away at ISIS control surrounding Mosul, advance into the city from various angles, and leave an open corridor out of the city to allow for an ISIS retreat back to Syria. Turkey, which already has troops present in northern Iraq to fight Kurdish Workers’ Party (PKK) forces, and has sponsored its own Sunni Iraqi proxies, has failed to secure an official role in the fight. It has nonetheless amassed forces along the Turkish–Iraqi border and threatened a more large-scale invasion into the Mosul area.

In short, each major player has different interests in the Mosul campaign, and will want to advance those interests while preventing rivals from doing the same.

Among the outside forces, Iran is one of the more intriguing. Long the United States’ main opponent in Iraq, Tehran’s immediate goal—to help the Iraqi government expel ISIS from Mosul and its surrounding areas—now aligns at least partly with Washington’s. Yet in the chaos of today’s Middle East, achieving that simple objective will present Iran with a host of challenges.  

NO NEW FRIENDS

Since the fall of Saddam Hussein in 2003, Iran has been closely involved with its neighbor Iraq. Tehran’s Iraqi Shiite allies, long suppressed under Saddam, now dominate the country’s politics. For Iran, which is short of friends in the region, Iraq’s transition from a hostile neighbor to a co-religionist ally has been a boon, and safeguarding the Iraqi state is now one of Tehran’s vital security interests.  

The basis of Iranian power in Iraq resides in Tehran’s support for Shiite militias and their politically powerful commanders. Iran’s Islamic Revolutionary Guard Corps (IRGC) has spent well over a decade training, funding, and organizing these clients. Today, the militias operate under the partial command of Major General Qassem Soleimani, the chief of the Quds Force—the elite IRGC division in charge of extraterritorial relations. Quds-trained militias are active supporters of Bashar al-Assad in Syria, and have been central to the war against ISIS in Iraq, where they have earned a reputation for sectarianism.

The militias have been a blessing and a curse for Iran. After ISIS’ 2014 takeover of much of Iraq, the Revolutionary Guards helped establish the popular mobilization forces (PMF), an umbrella organization of Iraq’s major Shiite militias. The PMF, legally sanctioned by the Iraqi government, has given pro-Iranian forces more legitimacy, greater freedom to operate, and a prominent role in the war against ISIS. Iran and the IRGC have thereby gained greater influence in Iraq’s political and security landscape.

Yet although the PMF has been central in the war against ISIS, its repeated abuse of Sunni civilians has dogged its reputation. In turn, the PMF has been sidelined from the main thrust of the Mosul campaign, in large part because Washington, Ankara, and others fear that the fighters would exact revenge on Mosul’s Sunni civilians. Since the militias are mostly IRGC clients, Iran will be blamed for any trouble they make in upcoming operations. The militias’ parochial disputes make Iran look bad, and associate it with a type of sectarianism that Iranian authorities—especially Supreme Leader Ayatollah Khameini, who outwardly stresses pan-Islamism over pan-Shiism—officially reject. (Not enough, however, to reject the militias.)

The PMF, legally sanctioned by the Iraqi government, has given pro-Iranian forces more legitimacy, greater freedom to operate, and a prominent role in the war against ISIS.

Iran also wants to keep the Iraqi government as an ally. Iraq is not only a neighbor but also one of Iran’s two state friends in the Arab world, alongside Assad’s Syria. Baghdad and Tehran share economic ties, and security concerns about Saudi Arabia and Sunni extremism more broadly, but their relations are tempered by Iraq’s closeness to the United States. Washington provides Baghdad assistance that Tehran cannot match: in the military sphere alone, U.S. airpower and on-the-ground support have helped Iraq achieve major gains against ISIS. Iran and its militia clients are uncomfortable with the United States’ involvement in the war—U.S. pressure has forced Baghdad to sideline the militias in key operations, and U.S. troops and military assets have been re-introduced to Iraq. Tehran has tried to use its Shiite clients, who have threatened to target U.S. forces, to make a return to the country seem unattractive for the United States. Even so, Iran has ceded a frontline role in Mosul to the U.S.-backed Iraqi military.

TROUBLE AHEAD

Iran’s interests in Iraq are thus not straightforward: it needs both the government in Baghdad and the Shiite militias to succeed in their own ways. The militias must continue to expand their influence domestically and in Iraq’s security sector. The more critical territory the militias effectively control (such as military bases, highways, checkpoints, border crossings, and key towns and villages), the easier it will be for the IRGC to conduct its business in Iraq. Iran needs the Iraqi government, however, to reassert its authority in Mosul and to have that authority appear legitimate to the largely Sunni residents of the area. To do that, sectarian abuses must be avoided. For now at least, Baghdad has been able to keep the pro-Iranian militias on the margins of the Mosul campaign.

The potential involvement of Turkey further complicates matters. Although Iran has better relations with Turkey than with Saudi Arabia, both are enemies in Syria, and perhaps now in Iraq, where Turkey has military advisors and is training proxies. To the objections of Baghdad and Tehran, Ankara has recently asserted its right to be involved in liberating Mosul. It has also mobilized a large force along the Turkish–Iraqi border, threatening that it is willing to advance toward Mosul.

A banner in Tehran featuring Ayatollah Khameini and Sheikh Nimr al-Nimr, a Shiite cleric executed by the Saudis, January 2016.
A banner in Tehran featuring Ayatollah Khameini and Sheikh Nimr al-Nimr, a Shiite cleric executed by the Saudis, January 2016.
Reuters

Turkey sees northern Iraq as part of its natural sphere of influence, and Turkish President Recep Tayyip Erdogan has spoken of his country’s historic claims on Mosul, a former Ottoman province. Participating in the city’s liberation would help Ankara advance those claims and secure a more lasting military presence in northern Iraq. Regardless of the endgame, an expanding Turkish presence in Iraq would be seen as a direct threat to Iranian interests, and as an illegal invasion by the militias and by Iraq’s government. In reference to Turkey’s threats and troop buildup, Iraqi Prime Minister, Haider al-Abadi, stated: “We do not want war with Turkey, and we do not want a confrontation with Turkey… But if a confrontation happens, we are ready for it. We will consider (Turkey) an enemy and we will deal with it as an enemy."

The Iraqi city of Tal Afar, 40 miles west of Mosul, could be a trigger point for Iranian–Turkish tensions. Shiite militias backed by the Iraqi air force have been given the lead in the effort to retake the city from ISIS. That did not sit well with Erdogan, who recently stated: “Tal Afar is a very sensitive issue for us. We definitely do not regard [Shiite militia involvement] positively in Tal Afar and Sinjar,” and warned the PMF not to “terrorize” the region.

Tal Afar is a mixed Sunni–Shiite city largely made up of ethnic Turks. Most Shiites fled after the city was captured by ISIS, and many, including the Turks, worry that victorious Shiite PMF forces could take revenge on Sunni inhabitants. The PMF, meanwhile, has responded to potential Turkish involvement in Tal Afar by stating that any Turkish forces will be considered as enemies, with the spokesman of the pro-Iranian Asaib Ahl al-Haq militia cautioning: “We already have plans to confront any intervention by [Turkish forces].”

The Iraqi Kurds could pose a similar problem. Iran and the IRGC have good working relations with Iraqi Kurdish leader Masoud Barzani and his Peshmerga; Iran’s Shiite clients, however, do not, having clashed with the Peshmerga several times already. Those tensions will be in the background during the Mosul operation and its immediate aftermath. But Mosul is the biggest prize so far in Iraq’s war against ISIS, and all sides will want to gain from it. Shiite militias have already warned the Kurds and the Turks about entering Mosul, but it’s unlikely that either will listen. Peshmerga leaders have stated they will not enter the city, but with so many competing forces closing in on the same general region, the potential for violent misunderstandings is high. 

To avoid further escalation, Iran needs to avoid serious clashes between Turkish, Kurdish, and Shiite interests in Mosul. Iran’s preference, therefore, is for the Iraqi government to take the city/ But tensions over the level of militia involvement will likely persist as the battle continues and in any post-ISIS security vacuum. At least initially, ceding direct control of the city to Iraqi government forces, while also maintaining a role for the militias in the surrounding areas, would enable Iran to keep a foothold in the Mosul theater and press its interests when it needs to. But the occupation of Mosul by any outside power—whether Kurdish or Turkish—would be anathema to the IRGC, and likely resisted outright by the militias.

WHOSE IRAN?

Behind all these calculations is a tension at the heart of Iranian–Iraqi relations. The government of Iranian President Hassan Rouhani is theoretically responsible for Iranian policy in Iraq. Yet Rouhani’s actual influence in Iraq is a distant second to that of Soleimani and the IRGC. In fact, Soleimani, due to his revered status among the Shiite militias, is the most influential Iranian politico in Iraq today. Because of Soleimani’s close relationship with Khameini, and the latter’s endorsement of the former’s regional strategy, Rouhani has little choice except to follow the IRGC’s lead.

That makes a difference regarding the policy Iran actually pursues in Iraq. Compared to the IRGC, the Rouhani government is more inclined toward compromise, and favors the influence that comes through legitimate relationships with other foreign leaders and governments. Rouhani is much less invested in the Shiite militias than the IRGC, and while those groups might serve Iran’s interests, they take their orders from Soleimani. Were Rouhani to have more control over Iran’s Iraq policy, one would expect to see less importance placed on militia clients in favor of more meaningful engagement at the state level. That would put more distance between Iran and Iraq’s paramilitaries, and make Tehran less culpable for their behavior.  

The rivalry between Rouhani and the IRGC should also be seen in the context of Iran’s domestic politics. The IRGC has long dominated Iranian policymaking in the Middle East, and the Rouhani government has not seriously challenged it in that arena. Rouhani has, however, wrestled with the IRGC over a host of other issues, from the nuclear deal to the expansion of trade with the West. Those turf disputes and larger ideological differences between the hardliners and moderate reformists fuel the political divide in Iran. 

Iran’s moderates have made huge gains under Rouhani, especially representation in the parliament and the Assembly of Experts, a clerical body that could determine the next supreme leader. These gains are inherently threatening to the hardliners (including the IRGC), who will be eager to defeat Rouhani in the next election in June 2017. Belligerent actions by the IRGC, including aggressive harassment of U.S. Navy vessels in the Persian Gulf and its numerous arrests of dual citizens, might be part of a campaign to undermine Rouhani’s efforts at international engagement with the West.

Could the IRGC pursue a similar approach in Iraq? Expanding the fight in Iraq doesn’t suit the IRGC’s interests at present because it needs U.S. airpower and military assistance to defeat ISIS, but it could make sense in the context of heightened tensions with the United States or Turkey in a post-ISIS context. Contentious election-year politics in Iran could also increase the potential for IRGC adventurism, as could an escalation in the Iraq conflict by Turkey or the Shiite militias. 

The battle for Mosul is the most important step in Iraq’s war against ISIS thus far. All major players in the region want to liberate the city, but their competing interests will make any post-ISIS scenario precarious. Iran has so far managed to balance its interests between the government in Baghdad and its Shiite clients. Yet intersecting Turkish, Kurdish, and Shiite claims to Mosul and its surrounding areas, combined with political rivalries at home, might make that balancing act difficult to maintain.  

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