Scenario for a major offensive against IS's biggest stronghold in Iraq.

The Iraqi army and its coalition against the Islamic State are urgently planning a blockade and offensive to retake the city of Mosul from the militants.

Kurdish armed forces fire rockets at ISIS in southeastern Mosul. Photo: Reuters.

According to the BBC, plans for the upcoming battle by the Iraqi army, with support from the US-led coalition against the Islamic State (IS), to retake Mosul, IS's strongest stronghold in Iraq, are gradually being revealed.

British Defence Minister Michael Fallon said military coordination agreements were finalized on September 23. He revealed that "the siege of Mosul will begin in a few weeks" with the goal of liberating Iraq's second-largest city "within the next few months".

Turkish President Recep Tayyip Erdogan even specifically announced the date for launching the attack on Mosul as October 19th.

Multiple stages

According to scholar Michael Knights of the Washington Institute for Near East Policy, what can be said with certainty at this point is that the campaign to liberate Mosul will consist of multiple phases.

First, a logistical base for the operation had to be established at Qayyarah Air Base, 60 km south of Mosul, which Iraqi Security Forces (ISF) recaptured in early July. Since then, authorities have upgraded the base to accommodate transport aircraft. From here, ammunition, fuel, and food would be transported directly to the front lines by air instead of being transported by truck from Iraqi supply depots near Baghdad, quite far from Mosul.

Approximately 560 American military advisors arrived at Qayyarah Air Base to guide and support the plan to attack Mosul. American and French long-range artillery systems were also deployed, including mobile assault guns and rocket launchers capable of directly striking Mosul within 20 seconds with high accuracy.

Enclosure

Shiite Muslim Popular Mobilization Forces will be stationed in sparsely populated rural areas and on roads south of the Qayyarah air base and west of Mosul. Photo: AFP.

The Qayyarah base also served as a staging point for Iraqi forces participating in the liberation of Mosul. These were primarily Iraqi soldiers who had withdrawn from across the country to join multi-ethnic and multi-sectarian fighting units.

There are approximately 11 special forces brigades ready for attack, each with around 2,000 personnel. Five other units from paramilitary police and tribal forces, with nearly 6,000 personnel, mostly Sunni Muslim Arabs from the greater Mosul area, are also on high alert.

Kurdish Peshmerga forces, along with some Christian and Kurdish-backed Kakai paramilitary police units, are besieging Mosul in the northeast and will tighten the siege from that direction.

Another plan was devised, allowing Shiite Muslim volunteer security forces from southern Iraq to indirectly support the battle to retake the city without causing panic among the Sunni Muslim majority in Mosul.

The Shiite Muslim Hashd al-Shaabi (People's Mobilization) forces will be deployed to protect sparsely populated rural areas and roads south of the Qayyarah air base and west of Mosul, but they will not participate in urban fighting.

Attack

Forces involved in the fighting in Mosul. Graphic: BBC.

The next phase of the campaign involves a multi-stage offensive into the suburbs of Mosul. The main assault will be organized along the Baghdad-Mosul highway on the west bank of the Tigris River and will halt once forces reach the southern suburbs of Mosul.

Another assault force could penetrate the desert west of Mosul, along oil pipelines and roads aimed at blockading the city, preventing ISIS from bringing in reinforcements or fleeing to Syria.

The final formation could attack Mosul from the east bank of the Tigris River, launching a surprise assault on the eastern flank of the city.

Scholar Michael Knights believes this phase will unfold in waves with inconsistent effectiveness: some days it will be easy to advance deep into enemy territory, other days it will encounter fierce resistance at a strong IS defensive position, or the advance will have to halt to wait for supplies.

At that time, Iraqi Security Forces and Popular Mobilization Forces would pour into the Mosul desert with large convoys, supported by coalition fighter jets, to eliminate the stubborn ISIS fighters.

November and December 2016 will be the time when the main battle begins. First, a command center to oversee operations will be established in a location near Mosul, where defenses can be easily deployed, to provide Iraqi security forces and the anti-ISIS coalition with a safe staging area.

Protecting the lives of the local population is also a complex issue. Approximately 700,000 people are likely still holding out in Mosul. Once the liberation forces gain control of the Mosul outskirts, people will begin to pour out in large numbers because ISIS will no longer be able to stop them. ISIS fighters could easily blend into the crowds to cause instability. This is why the anti-ISIS coalition is reluctant to approach Mosul before they are ready to take over the entire city.

Fall

For months, the anti-ISIS coalition has been closely observing ISIS tactics and defenses, carefully studying how ISIS moves, according to the BBC.

Michael Knights suggests that airstrikes will intensify in areas where the anti-ISIS coalition wants to break through ISIS's defenses. ISIS leaders will be the most intensely hunted targets.

However, IS will likely not be able to fight effectively in all areas of Mosul because the city is too large.

Instead, around 2,000-3,000 IS fighters will likely choose a few key areas to hold out. The western administrative center of Mosul is a symbolic location. The liberation campaign can only be declared victorious when it has complete control of this area.

When IS strongholds in the city collapse, the final stabilization phase of the operation will be implemented. Stabilization forces need to find a way to distinguish fleeing IS fighters from displaced civilians. Law and order in Mosul also need to be quickly re-established.

According to VNE