A U.S. contribution could help blunt ISIS advances in at least three ways.
Encouraging signs have emerged that the collapse of federal government control in Iraq may have slowed and that Baghdad is beginning the transition to counteroffensive operations to regain ground. Massive mobilization of largely Shiite volunteers has given Baghdad an untrained but motivated "reserve army" that can be used to swamp cross-sectarian areas around the Iraqi capital. All available formed military units have been pulled out of reserve and brought toward Baghdad to defend the capital. In this effort, all Department of Border Enforcement units have been relocated from the country's borders, and Iraqi army and Federal Police units have been redeployed from southern Iraq. Isolated federal government units are scattered across northern Iraq, in some cases hanging on against Sunni militants with the support of adjacent Kurdish forces. Fighting is now taking place on five fronts:
- Southern Salah al-Din. In the Tigris River valley (TRV), the government is fighting to regain control of the mixed Sunni-Shiite areas up to sixty miles north of the capital, with the northernmost point being the "stop line" at Samarra, beyond which Prime Minister Nouri al-Maliki dictated there be no further retreat. This line appears to be holding. Between Samarra and the massive army depot at Taji, on Baghdad's northern flank, the federal government is contesting insurgents' control by using its ground and aerial forces, seeking to maintain highway lines of control to Samarra.
- Diyala River valley. To the northeast of Baghdad, in the Diyala River valley (DRV) and adjacent corridors, the government is fighting to protect Sunni-Shiite areas on the main highway between Baghdad and the Iranian border. The Badr Organization, an Iran-backed paramilitary group, has historically maintained a close focus on Diyala and today dominates Iraqi military and police paramilitary forces in the province. Baquba, the provincial capital, is now under attack from insurgents led by the Islamic State of Iraq and al-Sham (ISIS).
- Western Baghdad "belts." In Baghdad's outer suburbs to the west (Falluja, Karma, Abu Ghraib) and the south (Jurf al-Sakhar, Arab Jabour), ISIS-led forces are probing the capital's defenses, and other militant groups are periodically shelling Baghdad International Airport. The insurgents seem to have lifted the government's siege of Falluja, but for now nearby Ramadi remains loosely under combined federal and provincial government control.
- The Kurdish front. The Kurdish peshmerga have moved into the disputed districts claimed by both Baghdad and the Kurdistan Regional Government (KRG), filling the vacuum left by collapsing Iraqi army units. Though the Kurds are mostly holding back from attacking ISIS, they have inherited areas such as Jalula where ISIS was fighting the Iraqi army and regularly killing Kurdish civilians before the uprising. Skirmishes meanwhile have been reported all along the KRG's new front line, and a number of Kurdish troops have been reported killed in social media martyrdom statements.
- Jazirah and Mosul. In the upper TRV and the Jazirah desert abutting Syria, the insurgents are consolidating their position in the absence of government forces. However, in Bayji, an oil-refining center, and Tal Afar, a large Shiite Turkmen town west of Mosul, the government still holds pockets of terrain and is reinforcing its outposts with small contingents of air-transported Iraqi special forces.
In the TRV and DRV, the government will likely be able to prevent the further expansion of ISIS and insurgent uprisings. Cities like Samarra, Baquba, and Muqdadiyah will remain under government control because both old and new Shiite militias are deeply committed to those fights and are being deployed in great numbers. Furthermore, Shiites make up significant increments of the population in these cities and their rural suburbs: rather than ISIS igniting the dry tinder of discontented Sunni populations, the group's operations will be frustrated by the large Shiite populations in the Baghdad-Samarra-Muqdadiyah triangle. Baghdad can also probably focus sufficient forces close to its center of command and logistical base in order to maintain control of the capital's western arc. The Kurdish front will remain mostly static unless the federal government can craft a very attractive grand bargain for the Kurds, a scenario that may be impossible under Maliki's leadership.
The final front, including the more open desert areas leading from Samarra to Mosul, will be one of the most difficult for the federal government to control. The largely Shiite "reserve army" is probably limited by its lack of training, equipment, and logistics to fighting defensive battles in the capital and the mixed Sunni-Shiite areas 60 to 90 miles north of Baghdad. Only Baghdad's regular armed forces, utilizing armored vehicles, heavy weapons, and air forces, stand a chance of making the long-distance movement across 250 miles of hostile terrain. Even then, significant numbers of such units will be needed for potential fights in Tikrit, Bayji, al-Sharqat, Tal Afar, and Mosul. Probably as many as 40 out of the remaining 180 or so Iraqi army and Federal Police combat battalions will be required if armed force is required to reconquer these areas.
Implications for U.S. Policy
If Iraq's government makes painful compromises to win back Sunni Arab and Kurdish support, U.S. security cooperation with Iraq will increase, as evidenced in President Barack Obama's speech today.
But if the United States does intervene, the correct subtheater is not the areas immediately around Baghdad and the DRV. These battlefields are likely to witness messy, morally ambiguous fights where sectarian cleansing could be widespread. As Gen. David Petraeus noted in a recent panel discussion, the United States cannot be "the air force for Shia militias, or a Shia-on-Sunni-Arab fight." If the militia-led forces around Baghdad try to go north of Samarra into the Sunni heartland, a sectarian Gotterdammerung could follow and the United States should not add another layer of complexity to the resultant fighting or become too closely associated with it. Indeed, the United States needs to carefully monitor the sectarian situation in mixed areas, noting that Shiite militias in Baghdad have already begun marking Sunni homes with red crosses as a warning to leave. The Iraqi government needs to be warned in the strongest terms to crack down on such behavior, which is as potentially destabilizing to Baghdad's security as any of ISIS's plans.
The United States should also focus its effort on three areas where Washington can make a significant contribution to the effort to roll back ISIS influence in northern Iraq:
- Splitting the insurgency. Fighting through the Sunni communities of the north is a daunting prospect and might only aid insurgent recruitment. Better would be to aim for a partial restoration of government authority through agreement with more moderate elements of the uprising. The military councils that rose up to exploit ISIS's success at Mosul include many unsavory elements from the Saddam Hussein regime, but these are desperate times. Many Sunnis would react favorably to an offer of increased local autonomy that still allowed for the provision of federal government services and also avoided crushing military campaigns in their streets. The United States can play a key role in bringing together deal makers from both sides and keeping up momentum.
- Fostering federal-KRG security cooperation. Iraq's Kurds have moved forward in many, but not all, of the internal border areas where the federal military existed. Pockets of federal forces remain around Rashad, Tuz, Tal Afar, and Lake Hamrin. Even if Kurdish forces are not keen to drive westward against ISIS at this stage, KRG cooperation could greatly assist the reprovisioning of these forces from the northeast. Federal air forces based at Kirkuk can likewise assist KRG forces and have done so this week in some armed engagements. Close coordination between federal and KRG forces using the Combined Security Mechanisms was a U.S. specialty before 2011 and could be a low-visibility way of maintaining pockets of federal forces and minimizing "friendly fire" incidents.
- Maintaining federal launchpads in northwest Iraq. The road from Baghdad to Mosul is long, and Iraqi logistical arrangements are in chaos. The United States has direct experience from a period in 2003 of undertaking long-range road and helicopter advances up the TRV and toward Mosul. The United States is also well placed to help logistically sustain government-held air bases in largely unpopulated desert areas, delivering U.S.-provided supplies directly to the front rather than to Baghdad. U.S. airpower could, if required, defend such launchpads without getting drawn into complex sectarian fighting: any force that attacks such air bases, most of which are in remote areas, will be regarded as the enemy.
Michael Knights is a Boston-based Lafer Fellow with The Washington Institute.