Military vehicles of the Kurdish Peshmerga forces are seen southeast of Mosul. Thomson Reuters

As the great powers jam the door of Mosul for the last big battle, many of the Islamic State terrorists themselves cannot wait to get out of town.

“Mosul on Thursday looked empty and the terrorists demoralized, as hundreds of terrorists fled from Shirqat after its liberation on Thursday,” according to the Iraqi Christian news site Karemlash. Nearly all ISIS cadres in the Tigris River city of Hamam al-Ali, 20 miles south of Mosul, have fled with their families on desert highways heading to Turkey, the site reported, adding that ISIS preachers had closed many of the mosques or left clerics from other countries in charge of them.

“News of the capture of Shirqat was greeted with joy by many Mosul residents who took it as a sign that their freedom from Daesh rule is nearing, according to local sources in the city,” Daesh Daily, a war digest, reported Friday using the Arabic term for ISIS. “Daesh rule is facing a ‘state of collapse’ in Mosul, sources said, which would be intensified by the news of Daesh’s loss of Shirqat.”

Meanwhile, France dispatched its carrier, the Charles de Gaulle, on Monday so that its aircraft can join the air bombardment of ISIS in a few weeks. The US Army on Tuesday asked congressional authorization to send 500 more US troops to support the Mosul liberation, which US authorities say will need at least 24,000 trained, well equipped Iraqi soldiers. The United Kingdom, France, Germany, Canada, Australia, Turkey, Denmark, and Italy are giving air assets, hardware, and advisers for the campaign.

ISIS' losses on the ground in Nineveh Province as a result of bombardment and fire fights have been heavy the last two days. The Ninewa Operations Command reported Thursday that coalition warplanes killed 160 ISIS fighters and destroyed large numbers of vehicles and machinery in Safina, a district south of Mosul, according to Daesh Daily.

Counterattacks against Iraqi forces at the Qayara airfield were repelled with many ISIS personnel killed, according to Iraqi media and cited by Daesh Daily. More than 40 ISIS terrorists were killed in an unsuccessful counterattack on troops of the Iraqi 71st in the Qayara area, a Ninewa Operations source said, adding that it suffered no casualties in the attack.

Another 30 ISIS fighters were killed by coalition airstrikes as they attempted to attack Iraqi army troops north of Qayara, a Ninewa Operations source said, and local sources reported seeing the bodies of several terrorists floating in the Tigris River after the attack.

Despite the losses and the reports of disarray in Mosul itself, some military experts and humanitarian aid officials suggest a costly, protracted battle is ahead that neither Washington nor Baghdad are prepared for.

Approximately 20,000 terrorists are in Mosul and preparing for an assault, according to Kurdish Brig. Gen. Bahram Yassin, in an interview with Dan Davis, a retired US Army officer writing for Politico. That number would be close to twice the number of ISIS cadres that defended Fallujah in May, when more than 85,000 residents were expelled into the desert heat as a result of fighting in early June.

After the Fallujah liberation the Iraqi army discovered numerous tunnels crisscrossing the Fallujah district, some as many as 8 km long. Mosul has many tunnels as well, in addition to improvised explosives and booby traps that would stall the advance into the city, resulting in house-to-house fighting and massive civilian deaths.

A US Army Apache flies over the desert near Mosul. US Army Staff Sgt. Ryan Matson

The chief challenge at this juncture is the complexity of the coalition of Iraqi Security, Peshmerga, and Shia Popular Mobilization forces, and Tribal Fighters with no effective central command, Davis wrote. “The Iraqi Security Forces (ISF) are not strong enough to capture the city on their own and are dependent on other armed formations. Moreover, they do not have command authority over even the forces operating within their borders.”

Iraqi military leaders have promised that the combined military operation against Mosul will start by Oct. 15, but the central, unified command structure has yet to be seen.

Some optimist battle scenarios envision an insurrection immobilizing ISIS within the city limits. Prime Minister Haider al-Abadi publicly called for residents to rise up four days ago, and for months Iraqi media has reported citizen assassinations of ISIS clerics, officials, and police. Former Nineveh Gov. Atheel Nujaifi said in May that a force of 1,000 resistance fighters is in the city already, many of them former Mosul policemen.

Resistance of the citizenry has been reported by the Iraqi military, which has dropped millions of leaflets to all neighborhoods in the city advising residents to keep far away from ISIS military facilities and to call one specified number to give the Iraqi army tips on ISIS movements.

Despite scores of beheadings and grisly executions of citizens accused of using cell phones and computers during the last two months, Iraqi authorities report that hundreds of calls come in every day and Iraqi newspapers run stories daily with details of executions given by “local sources” in the city.

If ISIS command and control forces continue to degrade, and if the insurrection bubbles up with force in coming weeks, the major portion of the population might be able to shelter in place, as was the case in Shirqat this week.

“Daesh is vacating its local command centers in Mosul as well as emptying its weapons and explosives from the churches it had been using as storehouses, according to local sources who said that Daesh feared Mosul residents would reveal their locations and the Daesh sites would become targets for coalition airstrikes,” Ali Sada reported in Daesh Daily on Friday.

“Daesh members are in a state of fear, fearing revenge by residents with the advance of Iraqi troops as well as a potential uprising in Mosul against Daesh rule,” according to Sada.