Kurdish gunmen hold their rifles in front of a burning house of a Shiite militia member during clashes in Tuz Khurmatu, Iraq, on April 24. (Goran Tomasevic /REUTERS)

The front line south of this bleak and dusty town looks much as it did two years ago, when the Islamic State was the enemy and controlled a village less than a mile away.

Now, however, the Kurdish peshmerga fighters holed up behind sandbags and barbed wire are peering across the line at Shiite militias, ostensibly their allies in the fight against the Islamic State.

Whether their alliance will outlast the Islamic State is in question. The militants’ defenses have been crumbling fast across Iraq. An offensive for the city of Mosul, the Islamic State’s last major stronghold in Iraq, is likely by the end of the year, U.S. commanders and Iraqi officials say.

If the battle goes well, the defeat of the Islamic State’s self-

proclaimed caliphate in Iraq, at least in terms of the territory it controls, is on the horizon.

And so, too, are new problems — and potentially new conflicts. For the past two years, Kurdish peshmerga, Iraqi army forces, and Shiite militias and some Sunni ones have largely overlooked long-standing differences to confront the menace facing them. But their feuds and grievances — over vital issues such as the distribution of power, land, money and oil — have not been resolved.

Paramilitary forces and the Iraqi army are gaining ground on the Islamic State in western Anbar province. The assault comes as many Islamic State leaders are fleeing the city of Mosul, the group's de facto capital in Iraq. (Reuters)

[Inside ISIS: Quietly preparing for the loss of the ‘caliphate’]

The manner in which the war has been fought — by an assortment of locally armed groups, often with competing agendas — has compounded the existing problems with new and potentially more intractable disputes. Among them are the questions of who will govern the areas vacated by the Islamic State, also known as ISIS, and how.

“The moment there is what you might call victory against ISIS, then you are up against all the problems that caused this crisis in the first place,” said Yezid Sayigh of the Carnegie Middle East Center .

In the process of rolling back the Islamic State, Kurdish peshmerga forces have conquered areas that were under Iraqi government control, expanding the zone ruled by the semiautonomous Kurdistan Regional Government by about 50 percent.

Shiite fighters under the umbrella of the Hashd al-Shaabi — which includes powerful militias backed by Iran alongside groups of ordinary volunteers — have pushed far north into areas that were wholly Sunni. Syrian Kurdish forces with the People’s Protection Units have crossed the border from Syria to help out in the fight and have occupied positions adjoining those of Iraqi Kurdish peshmerga, their fierce rivals in an even more complex, intra-Kurdish feud.

The Sunni grievances that helped fuel the militants’ rise have not been addressed, which means the cycle of Sunni disenfranchisement, alienation and insurgency could begin again, Sayigh said.

It is a complicated and messy battlefield that could easily unleash new conflicts as the victors of the war turn on one another in a scramble to control the territories left behind.





Filling a vacuum

The ethnically and religiously mixed town of Tuz Khurmatu is one place where the tensions have erupted in armed conflict. Late last year and again in April, at least 12 people died in clashes between Kurdish and Shiite fighters.

The town, made up mostly of Turkmen Shiites, has a sizable Kurdish and Sunni Arab population. Since Kurds and Shiite militias drove the Islamic State out of nearby villages nearly two years ago, Tuz Khurmatu has been administered by the Kurds. But Shiite militias maintain offices in the town and control most of the surrounding villages. Front lines crisscross the area, and it is not considered safe to traverse them. In recent months, several suicide bombings blamed on the Islamic State have helped keep tensions high.

[Ignoring Turkey, U.S. backs Kurds in drive against ISIS in Syria]

But the militants are not considered the most serious threat any longer, said Maj. Mahmoud Fares Mahmoud, who commands the Kurdish post on the outskirts of Tuz Khurmatu that was involved in some of the shootouts with the militias.

“To be honest, the biggest threat now is the Hashd al-

Shaabi,” he said, referring to the Shiite militias, whose flags are visible about a mile away. “It’s very hard to deal with them. They are savage, barbaric people. They don’t recognize any alliances or treaties, so you can’t trust them.

“We regret that we invited them here and made an alliance with them,” he added.

The Iraqi government and its allies in the Shiite Hashd al-

Shaabi are just as mistrustful of the Kurds, whose president, Masoud Barzani, has publicly stated that the borders of a new Kurdistan are being “redrawn in blood” and that he will not relinquish any territory taken by the peshmerga in the fight against the Islamic State.

“This is totally nonsense,” said Kareem Nouri, a spokesman for the Badr Organization, one of the Shiite groups around Tuz Khurmatu. “No one has any intention of allowing anyone to redraw the borders.”

The central government hopes to reassert its authority over the areas controlled by Kurds after the Islamic State is defeated, according to government spokesman Saad Hadithi.

“Any change brought about by any one person taking advantage of the circumstances is a temporary thing,” he said. “It is against the constitution, and we will not accept it.”

[Top Islamic State official suggests the militants are feeling the heat]

The battle for Mosul may, however, only make things more complicated. For the first time since the war against the Islamic State was launched two years ago, the entire spectrum of forces ranged against it will be joining together, including Kurdish peshmerga, the Hashd al-Shaabi Shiite militias, a selection of small Sunni tribal forces, a couple of Christian forces and U.S. troops, who have begun deploying southeast of Mosul to serve as advisers to the mission.

Although the city of Mosul is mostly Sunni Arab, the surrounding towns and villages in the province of Nineveh are populated by the full range of Iraqi ethnicities, including Sunni and Shiite Turkmen, Kurds, Christians, Arabs, Yazidis and a small group called Shabaks whose religion is similar to that of the Shiites. All have conflicting visions of how the province should be run after it is fully liberated, and there are multiple proposals for ways to divide it into smaller provinces.

Iraqis are hoping to avoid future conflicts, said Assad al-

Asaadi, the spokesman for the Hashd al-Shaabi movement.

“We will have a lot of work to do after Daesh, it is true, and it won’t be easier than fighting Daesh,” he said, using an Arabic name for the Islamic State. “But for the coming problems, war will be our last option, because we are sick of war.”

The different factions are barely communicating, raising fears of a dash to assert control over the liberated areas, according to a senior Kurdish official, who spoke on the condition of anonymity to discuss sensitive subjects.

“Nobody is talking to one another,” he said. “All anyone cares about is to be the first one to hoist their flag in the center of the city. It’s going to be a huge mess.”

U.S. officials acknowledge the concerns and say they are aware of the potential for conflict after Mosul is recaptured.

“The fall of Mosul is not if, but when, and when that happens, we want the planning in place to fill the political vacuum and get the people back into the city,” said Col. Christopher Garver, a U.S. military spokesman. “That planning needs to happen.”

Read more:

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Today’s coverage from Post correspondents around the world