The long-anticipated offensive by Iraqi government and Kurdish Peshmerga forces to retake Mosul, supported by the United States, has begun. The exact evolution of the campaign is unpredictable, but eight issues are likely to shape its ultimate outcome.

What ISIS decides. It remains to be seen whether ISIS digs in for a protracted fight or cuts its losses in Iraq to fight another day. Instead of making Mosul their last stand in Iraq, they could flood into Syria, or, more likely, disperse into the vast Jazeera desert between Mosul and Anbar where it already has some facilities. A fight to the death in Mosul could not only be costly for the remaining civilians, but a dramatic defeat for ISIS in that city would mean a definitive blow to their organization and its worldwide standing. Their enhanced presence in Syria would add to the complications in that country, and a retrenching in the desert would mean that the fight against ISIS in Iraq would continue for some time to come.

The speed of military success in Mosul. There is a good chance that the operation will eventually succeed in uprooting a weakened ISIS from Mosul, but the speed with which victory is achieved can have a significant impact on the course of events. If the offensive turns into a protracted grind, various actors—including Iran, Turkey, the PKK or Shiite militias—are likely to try and shape events on the ground to their own benefit. The United States and its partners will then face the challenge of countering such interferences. The added time, however, could allow the United States to develop agreed upon plans for post-ISIS Mosul.

The Role of Shiite Militias. Prime Minister Abadi has vacillated on the question of Shiite militias’ participation in Mosul, but he did pledge on the first day of operations that the Iraqi Army and national police would be the only forces to enter the city, understanding that Kurdish Peshmerga are likely to go into the Kurdish parts of Mosul. Iran-backed Shiite militias comprising key fighting elements of the popular mobilization forces will reportedly be limited to securing supply lines for the advancing forces. But Abadi may lack the power to enforce these limits if Shiite militias decide to circumvent them. Militias were implicated in atrocities in the aftermath of the Fallujah liberation earlier this year. Were Shiite militias to enter Mosul or “screen” fleeing civilians, one cannot rule out complications on an even larger scale. Sunni-Shiite tensions in Mosul could spread across Iraq and foment more extremism.

Turkey’s Role. Tensions between Ankara and Baghdad over the presence of Turkish troops near Mosul continue to escalate. Turkish President Recep Tayyip Erdogan seems determined to carve out a role for Turkey in Mosul’s future, and, amid disagreements with Baghdad, may intervene at some point during the campaign. For example, Turkey has an interest in defending Sunni Turkmen against atrocities by Shiite militias, and in ensuring that its Sunni Arab allies are not excluded from post-ISIS governance. Ankara is also wary of the PKK and Kurdish People’s Protection Units (YPG) presence in the Sinjar region between Mosul and the Syrian border. Forceful Turkish intervention for any of those reasons could polarize the situation, produce a Shiite backlash, and complicate any sincere stabilization efforts by local stakeholders.

Tensions between Baghdad and the Kurds. Although the Kurds and the Iraqi government are cooperating against ISIS in Mosul, subsequent conflict between the two sides cannot be ruled out. Iraqi Kurds have refrained from pushing for independence not only to prioritize the ISIS threat, but also because of their disagreement with Baghdad on the status of Kirkuk and other territories now under Kurdish control. In the aftermath of the Mosul campaign, Kurdish President Massoud Barzani is likely to push for a new relationship with the Iraqi government, either through immediate independence or a preceding confederal arrangement for a specified period. Lack of agreement between Baghdad and Erbil on a way forward will heighten competition for Sunni support.

Local Governance. There are significant disagreements on how Mosul’s governance should be organized. The current thinking in Baghdad envisions governor Nawfal Hammadi and the provincial council assuming leadership in Ninewa, assisted perhaps by representatives of the central government and the Kurdish regional government. Whether this formula will be accepted and supported by Ninewa’s populace remains to be seen. There is also the question of whether Kurdish and minority-dominated districts of Ninewa will seek to become provinces of their own and whether they will be given the freedom to choose between joining the Kurdistan Region and staying as part of an autonomous Ninewa federal region.

Reconstruction and humanitarian needs. There does not seem to be any serious plan for the post-liberation reconstruction of Mosul. The Obama administration has coordinated with international organizations to provide for Mosul’s civilians who are fleeing the city before the liberation gets underway, but it has not revealed any programs for addressing longer-term issues, most importantly the resettlement of displaced civilians who cannot return after the fighting, as has been the case in other places retaken from ISIS. Further, given Iraq's badly strained financial conditions due to the low price of oil and the ongoing emergency, it is critical to help Baghdad formulate a plan for reconstruction. The alternative might be a repeat of the neglect demonstrated in Fallujah and Ramadi.

Addressing the Root Causes. The root causes of Iraq’s civil war involve the sectarian policies of previous Iraqi governments and the failure of the Iraqi political system to establish power-sharing arrangements. If Iraq does not address these underlying issues then some successor of ISIS will reemerge even if the group is defeated in Mosul. ISIS itself was born of the ashes of al-Qaeda in Iraq (AQI), which had been defeated in 2006-2009 but rebounded thanks to governance failures, increased sectarian resentment and broken deals during the second term of former Prime Minister Nouri al-Maliki.

Many in the region believe that the Obama administration views the Mosul liberation as a legacy project, a box it wants to check before the November elections. Sunni Arabs in particular fear that the Obama administration’s impatience and desire for quick gains will divert attention from more fundamental time-consuming issues of power-sharing and a new national compact.

It is critical to address the longer-term challenges so they don’t exacerbate Iraq’s terrorism and extremism problem. Resolving these issues, notably the balance between the center and the regions, is key to ending the civil war in Iraq. An all-encompassing national compact among Iraqis will not be easy because it will require elaborate agreements on power-sharing at the center, and federalization, confederation or decentralization among local communities. Still, the conflict will persist in the absence of such agreements.

A successful campaign in Mosul has the potential to be an important milestone in the process of reconciliation, but only if the post-campaign period is given due attention. Otherwise, even victory in Mosul could ultimately just mark the beginning of a new phase of the Iraqi civil war.

Zalmay Khalilzad is a Counselor at CSIS. He was the US Ambassador in Afghanistan, Iraq and the UN. He is the author of a new book: The Envoy: From Kabul to the White House: My Journey through a Turbulent World, St Martin's Press.

Image: Iraqi T-72 tanks pass through a highway checkpoint in Mushahada, Iraq on their way to Forward Operating Base Camp Taji, Iraq. Wikimedia Commons/U.S. Navy