Exactly two years after the capture of Mosul in Iraq by the Islamic State of Iraq and Syria, the second largest city in Iraq is under siege again. The warriors of the Caliphate appear to be fighting a losing battle as the US forces have teamed up with the Iraqi army to recapture the city. ISIS, it would be pertinent to recall, has already been driven out of other important Iraqi cities, notably Fallujah and Ramadi.

Mosul is the last Iraqi city held by ISIS. Should the consummation materialise, as seems possible a week after the hostilities began, the fall of Mosul will be as much a setback for ISIS as a feather in Barack Obama’s cap three weeks before the US presidential elections.

International relations can on occasion be quirky. If the ISIS capture of Mosul in September 2014 was the high watermark of its seemingly forbidding surge Rs initially in the Arab world and then further afield Rs its expulsion from Mosul would mark a major setback for a group that has steadily been losing territory in Iraq and Syria. Aleppo in Syria and Mosul in Iraq have in recent weeks emerged as the two storm-centres of the battle against ISIS and state repression at another remove. The Iraqis are not planning to storm Mosul, and the offensive appears to be proceeding at a measured pace.

If defeated, ISIS will no longer control any major centre in Iraq and will largely be reduced to a rural insurgency within the country. In the event of the Caliphate meeting its virtual eclipse in Iraq, it will still have a fairly strong presence in Syria… despite Russia’s bombing from the skies.

The importance of Mosul in the fundamentalist geostrategy of ISIS cannot be discounted. It bears recall that the ISIS leader, Abu Bakr al-Baghdadi, had declared the Islamic State at the Grand Mosque in Mosul.

Thus was the Caliphate able to surge across Iraq as the country’s army collapsed in one city after another in the face of the fanatical onslaught. The Islamist capture of Mosul reaffirmed the inbuilt strength and confidence of ISIS two years ago, and the threat it posed to all of Iraq. The very possible loss of Mosul now will be a near-crippling blow. The risk of losing the city where the Caliphate was founded is dangerously real; it will be as much a strategic as a symbolic defeat that is bound to shake the entity to its foundations.

Arguably, it could lend a new dimension to the migrants crisis as fears of a massive civilian exodus are not wholly unfounded. The battle for Mosul will almost inevitably drive out civilians. Small wonder that the Iraqi government and aid groups are worried about yet another humanitarian crisis.