In Mosul, Islamic State’s defeat. But will it stick?

After nearly nine months of street- by- street fighting and the deaths of thousands of civilians, Iraq’s second largest city, Mosul, has been liberated from the grasp of the Islamic State. The victory wrests from the world’s most feared militant group any hope of an Islamic caliphate in the heart of the Middle East. And it delivers a crushing setback to an organization bent on killing American and European civilians wherever they can be found.

Iraqi Prime Minister Haider al- Abadi’s government deserves a degree of praise for this pivotal moment. After sweeping into Mosul in 2014, Islamic State went on to seize much of northern Iraq, governing with a rank brutality that entailed public beheadings and the use of women as sex slaves. Iraq’s armed forces regrouped and, town by town, began retaking territory. The 252day fight to retake Mosul was, as Lt. Gen. Stephen Townsend, the top U. S.- led coalition commander, put it, “the most significant urban combat to take place since World War II.”

The triumph is a moment to savor. But it also presents Baghdad with a new challenge: ensuring Islamic State doesn’t mount a comeback.

Fighting will continue in a few smaller cities and towns still held by Islamic State, but Iraqi forces have them surrounded, and they likely will fall in a matter of months. As before, Iraqi forces will get a vital helping hand from U. S.- led coalition air strikes, training and intelligence. But keeping Islamic State from re- emerging as an existential threat in Iraq shouldn’t — and won’t — fall on the shoulders of the U. S. Ultimately, it will be up to the Iraqi government and Iraqis.

We hope Baghdad’s Shiite- led government learned something from Mosul’s fall in 2014. The city, as well as other parts of northern Iraq, is home to large numbers of Sunni Muslims, a minority in Iraq that historically has been marginalized by the country’s Shiite leadership. Islamic State militants are Sunni Muslims, and when they rolled in, Iraqi Sunnis either welcomed the militants or didn’t resist. If Abadi doesn’t want to see the Islamic State’s resurrection, he needs to convince Iraq’s Sunnis that they have a place in Iraqi society.

Leaders in Baghdad have talked of moving toward decentralization that shares the country’s oil wealth equitably among the provinces. Iraqis would also get more authority to set up their own security at the provincial level. That means, for example, Sunni- dominant areas would get a fair share of the country’s resources, and would not have to rely on Shiite forces for security. The idea has merit, but so far, Abadi’s talk of reconciliation with Sunnis has been just that — talk.

Abadi will also have to rebuild much of Mosul. In the city’s western half, which bore the brunt of the fighting, 15 neighborhoods suffered heavy damage and another 23 experienced moderate damage, according to the United Nations. An estimated 897,000 people have been displaced, and Mosul’s overall reconstruction tab is expected to reach $ 700 million.

The U. S. and its allies can help with reconstruction and the return of refugees. They can also help Baghdad restore stability and security to its war- torn regions. But when it comes to creating a climate of inclusion that immunizes Iraq from Islamic State 2.0, that responsibility falls on Baghdad’s shoulders. For Iraq’s sake, and for the sake of every nation seen by Islamic State as a target, Baghdad needs to assume that responsibility with the same resolve it used to retake Mosul.