The rapid advance of the Islamic State of Iraq and the Sham and its allies is the culmination of over two years of strategy by the renewed terrorist group. Previously "essentially defeated" by American, Iraqi, and Sunni Awakening forces, ISIS has since 2011 carried out a methodical campaign of resurgence, abetted by the dissolution of Syria, the removal of US combat power, and the sectarian policies of Prime Minister Nouri al Maliki's government.
ISIS, which is leading the charge, is now seeking to consolidate its gains in Iraq and repeat its 2006 "Baghdad Belts" strategy that prefaced the worst sectarian bloodshed of the Iraq War. The challenge of removing the entrenched insurgent groups from recently gained territories will prove impossible in the short to mid-term without a number of key factors, including a change in the national government and renewed, significant international involvement in Iraq, both of which are unlikely.
It's a sectarian war ... but it isn't
Analysts have correctly pointed out that Maliki's polices have fueled Sunni anger and provided an opportunity for the ISIS to assert itself as the sword of the Sunnis. The ISIS offensive has been augmented by other Sunni groups, including the Naqshbandi Army, a collection of former Baathists and ostensible Islamists intent on reestablishing Sunni dominance, led by former Saddam Hussein aide Izzat Ibrahim al-Douri, as well as other jihadist groups such as Ansar al Islam and Jaish al Muhajideen. Additionally, the Sunni Muslim Scholars Association, a group of hardline religious leaders who resisted the US presence in Iraq, has attempted to credit mainstream Sunni resistance, and not ISIS, for the recent offensive. And Sheikh Ali Hatim Al-Suleiman, the emir of the Dulaimi tribal confederation, has characterized the uprising as a "tribal revolution," while at the same time denigrating "terrorists and ISIS," reported Asharq al-Aswat.
After the US withdrew from Iraq, Maliki failed to support and integrate Sunnis into the security forces. He also attempted to arrest prominent Sunni politicians (notably Iraqi VP Tariq al-Hashimi, finance minister Rafi al-Issawi and parliamentarian Ahmed al-Alwani), and his heavy-handed break-up of (mostly) peaceful Sunni protests against his policies, coupled with minimal concessions to the protesters, has fueled great Sunni bitterness toward his regime, which is widely viewed as an Iranian puppet state. But Sunni antipathy toward Maliki and the central government should by no means be conflated with Sunni approval of ISIS and the radical Salafi jihadist ideology it springs from.
Many leaders of the Sunni tribal Sahwa (Awakening) that took place between 2005-2008 became sworn enemies of al Qaeda and the Islamic State of Iraq (the predecessor of ISIS) after battling them into quiescence, and the Awakening leaders' hatred of the terrorist group's radical ideology and its violence toward enemies and civilians alike was animated and enduring. As late as the Sunni protests begun in 2012, many protesters were publicly distancing themselves from "al Qaeda" (ISIS) as the group attempted to insert itself into the vanguard of the popular movement. And certain tribal leaders, including the widely regarded head of the Sahwa (Awakening) movement, Sheikh Ahmed Abu Risha, are still holding out against ISIS near Anbar province's capital of Ramadi, while asking for support from former American allies.
"We've been fighting al Qaeda in Anbar for the past six months and we're ready to fight for another six months, but we need American support," Abu Risha told Bloomberg News on June 13.
At the height of its power, Abu Risha had lobbied for strategic partnership with America and proposed exporting the successful Awakening to other countries to fight al Qaeda. But he bemoaned loss of contact with his former American allies to journalist Eli Lake in late 2012:
"There is no contact right now," he said. "They don't visit at all. Ever since the United States withdrew, we haven't gotten anyone to visit."
In addition, the first two years of ISIS' military campaign in Iraq after US withdrawal ("Destroying the Walls 1 and 2") were devoted to the methodical assassination of prominent Sunni leaders who had fought the group during the Iraq War. This strategy was motivated by both revenge and the need to eliminate the group's most dangerous enemies: leaders who could continue to rally Iraq's Sunnis against the ISIS. As a result, although ISIS now has casual support among Sunnis who seek to use its military prowess to regain power, and has achieved tolerance from some tribal leaders who view ISIS as a necessary evil or have buckled in fear of the group, the mainstream nationalist Sunni agenda in Iraq greatly diverges from the violent zealotry of the terror group and its planned Islamic Caliphate.
Given time, this ideological gulf between mainstream Sunnis and the ISIS will undoubtedly manifest itself in greater conflict, as it did in Iraq as early as 2005, and as it currently does in Syria, where fellow Sunnis (including jihadist groups) have been battling the ISIS because of its greed and harsh ideology. But history is not on the Sunni nationalists' side. In the early years of the Iraq War, unsupported tribal "Awakenings" against al Qaeda in Iraq repeatedly failed; leaders and movements who resisted the group were assassinated or driven into exile. And the current incarnation of ISIS, flush with international support, recruits, thousands of jihadists freed from Iraq's prisons, and half a billion dollars looted from Mosul's banks, is stronger than it has ever been.
If the past is any guide, the likely Sunni-on-Sunni struggle in ISIS-held territory will not soon uproot the terrorist organization from the vast stretch of territory it has acquired. The Sunni Awakening only flourished with financial support, backed up by the American "surge" and counterinsurgency strategy, along with the cooperation of the central government and security forces supporting the groups. At present, while many Sunnis may despise the Maliki government and pine for a return to dominance in Iraq, they are once again facing the prospect of chafing under repressive Salafi-jihadists policies. But without outside assistance and organization, moderate Sunnis will be unlikely to decisively win what will be a protracted conflict.
But it will become a sectarian war
As ISIS tries to consolidate its rule over the Sunnis in areas it controls in Anbar, Ninewa, Salahaddin, and Diyala, and insert itself into the "belts" of small towns surrounding Baghdad, it will attempt to resume the high tempo "commuter insurgency" that sent waves of suicide bombers and anti-Shia forces into the capital during 2006. The most potent resistance to this offensive will be put up by the Iraqi security forces loyal to the government and by reinvigorated Shia militias such as the Mahdi Army (rebranded as the so-called Peace Army), the Hezbollah Brigades, Asaib al Haq, and the Badr Brigades, with support from Iran.
Barring quick, sweeping political accommodation, which is unlikely in the near-term, and significant, direct Western intervention, which is even less likely, the conflict could slip into the horrific sectarian ghettoization and murder that characterized the worst years of the Iraq War. Overt Iranian intervention in the capital and southern Iraq will only sharpen the sectarian divide, and all Iraqis in the path of this clash -- from the rabidly sectarian to the cosmopolitan resident of Baghdad who casually rejects sectarianism -- will be forced into a brutal struggle. In the north, the Kurds will seek to consolidate their gains in Kirkuk and prevent ISIS incursion, and only time will tell if they broker arrangements with the central government to wage an offensive against ISIS in the territory it has gained.
Thus, unless some powerful political accommodation occurs that redraws nationalist Sunni Arabs into the government in a significant way, Iraq will continue to broadly devolve along sectarian lines, with the outskirts of Baghdad and the edge of Kirkuk marking the major fault lines of the conflict.
The possibility of averting this schism and possible massacre lies with international brokerage that pushes the Iraqi government to come to accommodation with the Sunnis who are against ISIS. The ruling Shia coalition must also placate the Kurds, who will wish to make their gain of Kirkuk permanent and acquire rights to independently export oil from their territory. And any durable political reform would likely include steps that result in the eventual replacement of Maliki, whether in the form of his stepping down or being phased out via the institution of term limits on the office of prime minister.
Problematically, despite significant political pressure from prominent voices, Maliki has shown no inclination to step down, the West retains little leverage to drive political accommodation, and Iran has moved decisively to fill the power vacuum left by the US.
The endgame
The Iraqi government's military prospects of ejecting ISIS and its allies from much of their newly gained territory in Anbar, Ninewa, Salahaddin, and Diyala provinces appear to be slim in the absence of significant external support. ISIS' 2006 Baghdad Belts strategy, which called for the strangling of the capital city by controlling the outskirts and surrounding provinces, was so effective that it nearly caused the defeat of Iraqi and American efforts to stabilize Iraq. ISIS has now dusted off this battle plan and is attempting to reproduce it.
The 2006 Baghdad Belts strategy was so successful that it took more than 130,000 US troops with accompanying air and logistical support, combined special operations raids, the Iraqi military and police, and the Awakening forces all more than a year of concurrent operations to dislodge the Islamic State of Iraq, ISIS' predecessor, from Baghdad, the areas outside the city, and the outlying provinces.
This time, the isolated Iraqi government does not possess the combat power of the US Army, Marine Corps, and Air Force to partner with its military. The Kurds, who once provided tens of thousands of troops to fill or augment the ranks of the Iraqi Army, are seizing areas of interest as Iraqi forces flee the field of battle and they are holding their lines against ISIS and its allies. The Iraqi Army remains plagued by logistical troubles and it has limited intelligence, aerial and movement capabilities. And at least two divisions of the 14 division strong Iraqi Army as well as police and border forces have melted away during the ISIS onslaught. Most recently, ISIS seized the border crossings to Syria at Al Qaim and Al Walid, as well as the Turbail crossing to Jordan after Iraqi forces fled.
Before even thinking of retaking Mosul, the Iraqi military has to clear areas on the immediate outskirts of Baghdad. Complicating the problem is the influx of hundreds, if not thousands, of foreign fighters and more than 4,000 hardened jihadists who have been freed in jailbreaks at Tikrit, Abu Ghraib, Taji, Mosul, and Badush. The Iraqi military has been unable to eject ISIS and tribal allies from Fallujah for the past six months, a city just 30 miles from the capital. If the government and the military have not been able to clean up Baghdad's back yard, the prospects for quickly retaking Mosul, which is more than 250 miles from the capital, are grim.
In order to counter the ISIS offensive, the Maliki government needs to reach a political accommodation with mainstream Sunnis and the Kurds. But without a level of external military support (which is politically infeasible), that alone may be insufficient, and the government will be unable to reassert itself in the more distant provinces.