The battle for Mosul began late Sunday with an announcement by Iraqi Prime Minister Haider al-Abadi. A wide-ranging, uneasy coalition of forces is pushing forward to reclaim Iraq's third-largest city from the Islamic State, an effort complicated by more than 1 million civilians thought to be trapped in the city.

Iraqi forces, backed by a U.S.-led coalition, are joined by Kurdish soldiers, known as peshmerga, and Shiite militias. As The Post's Baghdad bureau chief, Loveday Morris, wrote last week, the mix of forces could ignite separate conflicts:

Under the military agreement, which lays out the plan of attack, only Iraqi special forces, army, police and volunteer fighters from the area will be allowed to enter the city, according to an Iraqi military spokesman, Lt. Gen. Yahya Rasoul. Iraqi troops will be allowed to move through and build up a presence in areas controlled by Kurdistan’s semiautonomous government, and sectors of the battlefield have been assigned to various Iraqi forces.
The role of the Shiite militias is “still to be determined,” Rasoul said, though they may be used to secure the outskirts of the city.
Tensions over power and land have already caused factions fighting the Islamic State in Iraq to turn their weapons on each other. Shiite militias have clashed with Kurdish peshmerga forces over the past year in the northern town of Tuz Khurmatu.

Morris and correspondent Kareem Fahim traveled with peshmerga and Iraqi special forces this weekend as the offensive got underway.

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