The battle for Mosul is about to become much more bloody.
After advancing slowly but surely against ISIS for the past 17 days the Iraqi forces are now at the gates of the city. They have captured almost 1,000 sq miles of territory, killed hundreds of fighters, and retaken dozens of villages.
The really hard fighting begins now as the battle becomes overwhelmingly an urban one two and half years after ISIS took Iraq’s second largest city.
The Iraqi security forces, and Kurdish Peshmerga, have advanced on three separate fronts from the north, east, and south of the city, all supported by U.S airpower. To the west are Iranian backed Iraqi Shia militia.
The latter remain a long way from the city limits for several reasons. Firstly, an ‘escape’ route for ISIS could allow any retreating column to be bombed in the desert by the Americans. Secondly, the militia want to surround the town of Tal Afar to prevent it being used as bolt hole for ISIS or as a supply route. Lastly, Mosul is a predominantly Sunni Arab city, and the presence of Shia militia could lead to sectarian violence. The Kurds are also being told not to enter the city in case of ethnic clashes.
The Kurds are strongest in the mountainous region to the north and northeast– which is controlled by the Kurdistan Regional Government which in theory is a regional component of the state of Iraq. The temptation to add a major city to their fledgling Kurdistan is great, but any attempt to so do would guarantee the fighting will continue long after ISIS lose control.
Below the city the Tigris river wends its way down to Baghdad through predominantly Sunni Muslim region before entering the Shia dominated south. All three, Kurds, most Sunni, and all Shia are determined to rid the country of ISIS, but that is about all they agree on.
The estimates of numbers of ISIS fighters inside Mosul range from 2,000 to 10,000. The higher estimates appear more likely to be true. Ranged against them are up to 60,000 men backed by air power, however, the battle terrain now favours the defender and urban warfare is notoriously difficult and bloody.
ISIS will use tunnels, snipers, booby traps, suicide bombers, oil filled trenches, and human shields to slow the advance into the centre. They have an unknown number of tanks and artillery pieces, and several hundred armoured vehicles. Up to one million civilians remain in the city, many forced to stay by ISIS. Mosul probably will be taken, but the human cost is likely to be enormous.
ISIS will choose to fight street by street as they fall back through the eastern suburbs towards the Tigris river which flows through the heart of the city. There are 5 bridges across the Tigris, three of which are thought to be functioning. As the Iraqi forces advance they will be forced into bottle necks near the river crossing.
ISIS can then choose to retreat to the western side of the city, blow the bridges, and then defend against any attempts to cross the river. This tactic would also mean the Iraqi forces might have to split some of their troop concentrations so that they skirt around the city and try and enter it from the west. Even if it loses control of Mosul, ISIS is likely to leave behind scores of fighters who will melt into the civilian population but emerge to engage in sporadic terrorism.
There are added complications: Turkey is watching events closely. The town of Tal Afar has a substantial Turkmen population. If the Shia militias enter it, Ankara may feel it has to enter the fray to safeguard them, and not to allow an Iranian influenced force to control the town. Turkey already has military personnel in Bashiqa, and re-enforcements may be on their way. Turkey also likes to remind its neighbours that Mosul has a Turkmen minority, that the city was part of the Ottoman Empire, and that the legal status of the city is unclear.
ISIS will almost certainly lose territory, men, munitions, and kudos. The ideas which support the jihadi Salafist terror group will only be damaged – they will survive to kill innocents another day.
Mosul matters for so many reasons, its size, its location, its symbolism, but mostly for its people. The battle for the city has the potential to be one of the most awful urban battles since WW2. If it is not waged successfully on both the military and political level, the fighting will not end when ISIS loses control.