[size=52]Iraq Launches Offensive to Retake Mosul From ISIS Occupiers
Airdropped Leaflets Warn of Attack on ISIS in Mosul 0:20
The Iraqi army, directed by U.S. advisers, launch an offensive Sunday aimed at wresting Mosul from the hands of ISIS and ending its brutal two-year occupation.
Iraqi Prime Minister Haider al-Abadi announced late Sunday that the operation to retake the last ISIS-held city in the country had begun — but plans for it were known long before.
Earlier Sunday, Hadi Al-Ameri, commander of the Badr Shiite organization; Ahmed Al-Asadi, a spokesman for the Popular Mobilization Forces, the militia coalition supporting the opeartion; and Gen. Shaker Jawdat, commander of the federal police, arrived at the military base in Qayyarah, a senior security official said.
[size=46]Play[/size] What You Need to Know About Mosul 2:32
Iraq's air force dropped leaflets warning Mosul residents that the liberators are coming, and the Baghdad government directed broadcasts directly into the heart of the occupied city.
Meanwhile, Iraqi forces have circled the country's second-largest city and cut off any supply — or escape — routes that the ISIS fighters holed-up in Mosul could use.
The army is following in the footsteps of Alexander the Great, the Persians, the Turks, the British and other conquerors who have fought over this ancient and strategic city on the Tigris River.
"It's going to be a bloody battle and a fight to the death for ISIS," David Phillips, who heads the Program on Peace-Building and Rights at Columbia University, told NBC News on Wednesday. "There is no escape for them."
Highway 47, which connects Mosul to the ISIS stronghold in Rakka, Syria, "has been seized by Kurdish Peshmerga forces," Phillips said. "So they have no alternative but to fight to death."
Mosul's location — and the fact that it's in Iraq's oil producing region — is the reason ISIS is so determined to hang onto the city.Pro-government forces drive in Iraq's eastern Salaheddin province, south of Hawijah, last week as they clear the area in preparation for the push to retake the northern city of Mosul. Mahmoud al-Samarrai / AFP - Getty Images
"It straddles a strategic transportation corridor connecting the Middle Eastern countries to Turkey and the West," Phillips said. "You don't really have to drive through Baghdad to get anywhere. But all the transport routes go through Mosul."
Seizing Mosul will not be easy for the Iraqi forces, who are preparing for guerrilla warfare against an enemy that has no problem using civilians as cover.
"The entire city is booby-trapped," Phillips said. "They've also dug a labyrinth of underground tunnels so they can pop up and shoot from different angles."
Earlier, Brett McGurk, the State Department official coordinating the effort against ISIS, warned that the Iraqis are taking on a ruthless and formidable foe.
"This will be a very unpredictable, very dynamic, very uncertain operation," McGurk said. "There are a lot of unknowns."
"We do not know what Daesh is going to do in Mosul," he added, using a U.S. government name for ISIS.An Islamic militant holds an ISIL flag and a weapon on a street in the city of Mosul, Iraq, on June 23, 2014. Reuters file
In addition, the fate of the thousands of Yazidi women whom ISIS fighters have taken as sex slaves and are believed to be holding in Mosul is one of the biggest unknowns.
"We're going to try to make sure that if Daesh escapes Mosul, which I don't think they'll be able to do, that they can't take these people with them," McGurk said. "It's one of most difficult questions, and we want to free these people. That's one of the key objectives of the operation."
In advance of the attack, McGurk said planners are working on a worst-case scenario that envisions 1 million internally displaced people. He said they are working with the Iraqi government, the Kurdish Regional government and various non-government organizations to position resources to help them. The operation has already raised $2.4 billion for humanitarian assistance.
"The plan is to keep people in their homes," McGurk said. "And the messaging that is ongoing now for the people of Mosul is to keep people in their homes."
The United States is also working closely with the Iraqis to set up a screening process to ensure that ISIS fighters masquerading as civilians don't slip through the cracks — and to keep in check the various ethnic and religious resistance forces that have been fighting against ISIS within the city.
The aim, McGurk said, is to "make sure that armed groups that are not fully under the full control of the Iraqi government are not part of the Mosul campaign."
Mosul is a cosmopolitan city that in normal times is home to about 2.5 million Assyrians, Kurds, Shabaks, Yazidis and Armenians, in addition to the Sunni Arabs. Historically, the city has been home to Christians and Jews, as well as Muslims. Since the war started, 1 million residents have fled Mosul.
"The concern is once ISIS is gone, Mosul residents will start settling scores with one another," Phillips told NBC News. "The fear is that Mosul could become another flashpoint for Iraq's further fragmentation."
U.S. military officials have not released any details about the attack, but they have made no secret it's going to happen.
The Iraqi government has also been beating the war drums.
"Today, you are closer than ever to being rid of the injustice, gore and brutality of Daesh," al-Abadi said in a recent radio broadcast.
Republican presidential nominee Donald Trump has complained that the warnings about the impending attack on Mosul have given ISIS leaders time to prepare.
Pentagon officials, however, say the strategy is aimed at bucking up Mosul residents and persuading the low-ranked ISIS fighters to give up before they are killed.