The loss of Mosul would be a serious and highly symbolic setback for ISIL. This is because Mosul is the city where ISIL publicly declared its caliphate in the territory under its control in late June 2014. ISIL had thereby for the first time established its alternative model of a jihadist state in the Middle East – a model that challenges the right to existence of all nation states in the Middle East, and particularly that of the artificial nation states in the Levant created by the European powers after 1918. Since late 2015, a broad and unequal alliance consisting of the Iraqi armed forces, the Kurdish Peshmerga, Shia militias, Sunni tribal fighters, and international troops commanded by the United States has been gradually pushing back the jihadists of the ISIL caliphate. This resulted in ISIL being cut off from its supply routes and losing its most important sources of income after the alliance recaptured a number of oil and gas facilities. As a result, the Syrian and Iraqi territory of the ISIL caliphate became increasingly smaller. In November 2015, Kurdish Peshmerga troops sent by the government of the autonomous Kurdistan region in Erbil captured the city of Sinjar in the north of the Ninawa governorate. Supported by US air strikes, Iraqi troops and Shia militias have been recapturing an increasing number of strategically important cities. These include Baiji, the major oil refinery city (October 2015), Ramadi, the capital of the western Al Anbar governorate (December 2015), and recently Fallujah, the second most important city in Al Anbar (July 2016). Some members of the attacking coalition reacted euphorically after several smaller towns in the vicinity of Mosul were successfully retaken. The Western members of the anti-ISIL coalition were also hopeful that Iraq's internal division could be overcome and that ISIL could be permanently weakened. The following brief review shows why this hope could be a pipe dream.

Iraq since 2003 and the Unresolved Religious Conflict between Sunni and Shia Muslims

After 2003, the United States destroyed the fragile balance of power between the different denominations, which had been dominated by Sunni Arabs (20 percent of the population). By systematically "de-Baathifying" the administration and disbanding the armed forces, the United States stripped the Sunni elite of its control over the governmental power structures and produced a power vacuum. Many Sunnis who had initially been willing to cooperate with the new order turned to an armed insurgency that eventually consisted almost exclusively of Sunnis. The vacuum was primarily filled by two opposing forces: firstly by the Shia opposition parties with their armed militias that had returned from exile or emerged from the underground, and secondly by the Sunni jihadist organisation Al-Qaeda in Iraq (AQI) - ISIL's predecessor organisation that had gradually infiltrated the country from abroad. After 1,300 years of oppression, the Shia Arabs (60 to 65 percent) came into power in the free elections held in 2005. Shia party leaders were suspicious of the Sunnis. Rather than sharing governmental powers with them, the Shia leaders excluded the Sunnis at the political level. This paved the way for AQI to start the first civil war in 2006, which left the governing Iraqi Prime Minister Nuri al-Maliki helpless.

The United States for the most part managed to end this civil war in 2008 with a major military effort. In the same year, the US concluded an agreement on the withdrawal of its forces with Prime Minister Maliki, who had regained political strength and demanded a full transfer of sovereignty. The US withdrew its troops from Iraq in 2011, leaving behind a country without a functioning democracy that had also not been pacified from a military perspective. Maliki, who managed to remain in office after the 2010 elections, stepped up efforts to limit the power of Sunni Muslims shortly afterwards. Up until 2014, he crushed all Sunni protest movements and took all power away from their democratic politicians. This political exclusion of Sunni Muslims mainly benefited ISIL, the successor organisation of AQI, which had relocated most of its operations to Syria after 2011 and then returned to Iraq in 2014. Having lost all political power, many Sunni Muslims sympathised or collaborated with ISIL, thus enabling it to establish the ISIL caliphate. The establishment of the caliphate not only exacerbated the vicious circle of religious violence, hatred, and revenge; it also cemented the de facto division of Iraq into three separate state-like entities: a Kurdish one (the Kurdistan region), a Sunni one (the ISIL caliphate), and a truncated "Shiastan" comprising Baghdad and the oil-rich southern governorates.

Tensions within the Anti-ISIL Coalition

The most powerful adversaries of the 4,000 to 5,000 ISIL fighters entrenched in Mosul are the 40,000-strong units of the regular Iraqi armed forces, the Iraqi police's anti-terrorism special units, andso-called Popular Mobilisation Units (al-hashd al-shaabi). These units are jointly advancing from the south. Consisting of approximately 100,000 fighters, the Popular Mobilisation Units are an umbrella organisation of Shia militias that was established in June 2014 when the spiritual leader of Iraq's Shia Muslims, Grand Ayatollah Ali al-Sistani, called volunteers to arms in order to defend Baghdad against the ISIL offensive. Kurdish Peshmerga units from the Kurdistan region are supporting their offensive in the north and east. Units from the international anti-ISIL coalition led by the US are also involved in the offensive.They particularly include US military advisers, whose number in Iraq has increased to roughly 5,000. The Iraqi armed forces and police forces want to make amends for the defeat suffered in June 2014, when 1,500 ISIL jihadists captured Mosul without facing much resistance from the 60,000 Iraqi soldiers and police officers, who fled the city while it was under attack. The Mosul fiasco caused most of the Shia-dominated armed forces, whose officer corps consisted almost entirely of corrupt followers of Nuri al-Maliki, to disintegrate.

The fall of Mosul also proved to be a millstone around Maliki's neck, and in August 2014 it forced him to hand over his office to Haider al-Abadi, a colourless Shia member of parliament and long-standing political companion. Abadi discharged numerous corrupt and incompetent officers and began not only to rearm and reorganise the armed forces, but also to restore their damaged fighting morale with the help of US military advisers. However, it will not be certain until after the Mosul offensive whether the newly-gained professionalism and combat strength of the Iraqi armed forces and police will suffice to drive ISIL out of the city and thereafter to enforce the Iraqi central government's authority in Mosul.

Abadi and his closest allies favour closer ties with the US and the West, whereas the majority of Baghdad's Shia power elite is pro-Iranian. A successful operation of the armed forces would not only be a success for Abadi, but it would also significantly increase the influence of the US, which lost most of its political clout in Iraq after the withdrawal of its troops in 2011. Iran was the main beneficiary of the US troop withdrawal. It provided a refuge for nearly all exiled members of the Shia opposition parties from 1980 until 2003. This means it can rely on their loyalty and gratitude now that they have gained seats and the power to vote in Iraq's parliament. As a result, most Shia members of the government in Baghdad as well as numerous leaders of the Shia Popular Mobilisation Units are today essentially controlled by Iran, which has been supporting Iraq with arms shipments, military advisers and air strikes against ISIL since July 2014. This led to Iraq becoming a semi-dependent client state of Iran in 2015.

The Shia power elite's weak support for Abadi, his limited authority and lacking room for manoeuvre at the political level are jeopardising his plans for the two most important reforms: the fight against corruption and political reconciliation with the Sunni Muslims. The primary source of corruption is Muhassasa, a system introduced in 2003 to apportion positions and offices among the ethnic and religious groups, which also promotes nepotism and permeates the government, the state, and the administration in all areas. So far, Abadi has been unable to prevail against the corrupt and reform-averse forces which dominate large parts of his own government, most of the Shia militias, as well as the legislative branch. Abadi's toughest opponent in this battle is Nuri al-Maliki, who is still serving as Iraq's vice-president. Using this office, which has been transformed into a bastion of his power, Maliki is systematically obstructing Abadi's attempts at reform and his offers for reconciliation with the Sunni population.

However, the Popular Mobilisation Units are the most unpredictable factor in Abadi's plan to recapture Mosul. These units stopped ISIL's offensive on the outskirts of Baghdad after the armed forces had disintegrated, and they subsequently played a crucial role in driving ISIL out of other Sunni cities. On the other hand, after recapturing a number of areas, they have also become notorious for excessive violence motivated by a desire for revenge against parts of the civilian Sunni population that they suspect of having collaborated with ISIL. Tens of thousands of Sunnis have been driven out of their homes since 2014, and thousands of others have been imprisoned or executed, or have disappeared without a trace. The fact that Abadi's government has so far failed to control the rampaging Shia militias has undermined the Sunnis' confidence in Abadi's ability to protect them.

Turkey's President Erdogan has been further complicating the situation by supporting the Iraqi Kurds of the Kurdistan region under President Masoud Barzani - both politically and economically - by opening the Turkish border for Kurdish oil exports. Following a request by the leaders of the Kurdistan region, the Turkish government has established a military base with 400 troops a few kilometres north of Mosul, where Kurdish forces are trained and supported for their fight against ISIL. Erdogan insists that Turkish units take part in the Mosul offensive against ISIL. Baghdad strongly opposes this participation and considers it a violation of Iraqi sovereignty. It has therefore already threatened to take military countermeasures. Turkey also functions as a protecting power for the al-Hadba alliance, a Sunni Arab alliance of parties in Ninawa that controls a tribal militia (also called the "Ninawa Army") comprising 4,000 fighters. The secular-nationalist Hadba alliance intends to become the dominant political force in Mosul after ISIL has been driven out of the city.

President Erdogan and other Turkish politicians have in speeches repeatedly hinted at Turkey's former claim to the Mosul region, which the young Republic of Turkey did not abandon until the 1920s, and which also involved a claim to leadership over the Turkic-speaking Turkmens both in Mosul and in the city of Tal Afar to the west of Mosul. This leaves no doubt that Ankara will do everything it can to function as a protecting power for Sunni Arabs and Turkmens when it comes to distributing the political loot after the victory over ISIL. Turkey wants to use these ethnic groups as a lever to exert influence and to counteract the ambitions of Iraqi Shia militias - and of Iran as their protecting power - in the Sunni north and west of Iraq.

ISIL between Defeat and Resurgence

The gradual implosion of the ISIL caliphate in Iraq, which lost its most important sources of income when oil and gas wells were recaptured, has weakened the caliphate's financial ability to guarantee its Sunni citizens administrative, medical and infrastructural services. The majority of Sunni Muslims living in the ISIL caliphate has already grown weary of the constant shortages and the brutal ideological regime run by ISIL, and the population's loyalty to the jihadists has begun to fade as a result. ISIL's forces are hopelessly outnumbered by the attackers and have established a defence system consisting of booby traps, fortifications, tunnels and trenches. Nevertheless, ISIL has already been forced to abandon several suburbs to the south and east of Mosul. It is to be expected that there will be a long and embittered struggle and fierce house-to-house fighting with numerous civilian casualties. International relief organisations and their partners in the Kurdistan region and in Baghdad are aware of this situation. They are expecting a humanitarian crisis with up to one million refugees who cannot be accommodated or cared for with the humanitarian resources that are currently available.

Apparently ISIL has already prepared for defeat in Mosul. It has by now transferred the majority of its fighters and leaders to Raqqa, its second "capital city" in the east of Syria, and to the ISIL province of Sirte in central Libya. ISIL leader Abu Bakr al-Baghdadi had already sent one of his two deputies and 1,000 fighters to Libya via Lebanon in late 2015. In addition, ISIL has called on its fighters and supporters to retreat to the Iraqi desert to continue the fight. ISIL does, in fact, still have loyal allies among some of the numerous Sunni Arab nomadic tribes living in the vast semi-deserts in western Iraq. This could make it easier to establish a new terrorist organisation experienced in guerrilla warfare. ISIL will be forced to compensate the damage to its reputation resulting from the expected fall of Mosul. It will therefore expand its branches in northern Egypt and southern Yemen and also carry out terrorist attacks around the globe more frequently. In order to achieve this goal, ISIL will probably increase the number of terrorist sleepers among the wave of refugees as far as possible and also activate its existing underground networks of followers and sympathisers in other countries of the Middle East, in Turkey, as well as in Europe. The organisation will most likely attempt to stabilise the number of its followers (which had recently been declining to some extent) by means of even more brutal terrorist attacks, especially in Europe, which are to be carried out by self-empowered "lone wolves" and activated sleepers.

The decisive question will be whether the Popular Mobilisation Units adhere to Haider al-Abadi's plan. Under this plan, the regular armed forces will primarily be in charge of recapturing and occupying Mosul, whereas the militias are to concentrate on securing the sectors behind the front line. If the militias submit to Abadi's authority and refrain from taking revenge on the Sunnis in Mosul, it could be possible to pacify the Sunnis and gradually bring the conflict to a peaceful end. If the militias do the opposite, new conflicts will emerge because it is unlikely that the citizens of Mosul will tolerate despotism and acts of revenge by an "occupying Shia army" without putting up resistance. Should Baghdad's attempts to pacify Mosul fail at the political level, ISIL would again inevitably gain popularity and renewed strength as the only true defender of the Sunni population. A victory over ISIL achieved purely at the military level and without subsequently restraining the Shia militias could therefore rapidly transform into a political defeat for Baghdad or, even worse, into a new round in the religious war between Shia and Sunni Muslims.

No Plan for The Day After

Neither Baghdad nor the Kurds in Erbil have a convincing strategy as to who will control Mosul as the undisputed peacekeeping power following a victory over ISIL. It is also unclear whether Baghdad wants to use fair political participation to reintegrate the Sunnis into the nation as a whole so as to restore Iraq's national unity. It is far from certain whether Baghdad's remaining state of "Shiastan", with its weak and internally divided government, will be able to stabilise Mosul at all. What is more, the Iraqi government is already facing a major dilemma because of its alliance with two competing powers – Iran and the United States.

It is beyond doubt that there will be fighting over the distribution of loot on the very day after the victory over ISIL, and that this will lead to suppressed conflicts of interest within the anti-ISIL coalition being reignited. Such conflicts could occur between Baghdad and the government of the Kurdistan region in Erbil, between Baghdad and Ankara, or between Baghdad's Shia government and the Sunni opponents of ISIL gathered in the Ninawa Army. The result could be chaos and military conflicts between all parties involved, in other words: ideal conditions for ISIL to recruit new followers and to rise like a phoenix from the ashes.

Following a potential victory over ISIL, one of the main lines of conflict would be between Baghdad and the Kurdish regional government in Erbil, which has already announced its intention to proclaim full independence several times. However, Erbil has repeatedly postponed this move, mainly because it has been engaged with fighting off ISIL and hosting 1.7 million refugees, most of which are Yezidis, Christians and Arabs from ISIL-held territories. If the Kurds do not cede the territory gained in Mosul and the surrounding areas to Baghdad following a victory over ISIL, this would probably renew their long-running conflict with Baghdad over the "disputed territories" in the north of the country, and particularly over the oil-rich territories in the vicinity of Kirkuk. The result would most likely be a military escalation.

Outlook

If Abadi fails to control the Shia militias after driving ISIL out of Mosul, and likewise fails to bring peace to Mosul's Sunni population and to thwart Kurdish and Turkish ambitions for power, it seems inevitable that he will be replaced by a pro-Iranian Shia hardliner from Baghdad's state elite before long. But regardless of who is in charge in Baghdad on "the day after", the future Iraqi leader will have to deal with permanent religious and ethnic conflicts as well as seemingly insoluble social and economic problems, many of which are related to demography. Iraq's annual population growth of 2.9 percent is the world's ninth fastest, and the country's population has more than doubled to an estimated 38 million since 1991 – despite several wars and a twelve-year UN embargo. Moreover, 60 percent of the population are under 25 years of age, and the Iraqi youth has little prospects for the future due to a lack of jobs and training opportunities as well as ingrained corruption within the government and the administrative sector. In order to earn a living, many young Iraqis have no other choice but to become mercenaries in the militias or to travel to Europe as refugees. Regardless of how and when the battle for Mosul ends, this deeply worrying trend will continue.

Wilfried Buchta holds a PhD in Islamic Studies and works in Berlin as a publicist specialising in Middle East-related topics. From 2005 to 2011, he served as a political analyst for the United Nations Assistance Mission for Iraq (UNAMI) in Baghdad. This article reflects the author's personal opinions.