The Iraqi government made a mistake that will allow Isis to survive by seeking to capture Mosul before eliminating other Isis safe havens in northern and western Iraq to which its fighters can retreat, according to a senior Iraqi leader.

“It would have been better first to eliminate Daesh (Isis) sanctuaries to which they can retreat when Mosul falls,” says Najmaldin Karim, the Governor of the oil province of Kirkuk, in an interview with The Independent. He says that half of Kirkuk province is still held by Isis and cited, in particular, the Hawija area, a notorious stronghold south west of Kirkuk city of Isis and previously of al-Qaeda in Iraq.

Iraqis in general are wondering if the long-delayed capture of Mosul will prove to be a decisive defeat for Isis and the self-declared Caliphate or will it return to guerrilla warfare and terrorism. Mr Karim believes that it will not be able to capture territory as it once did, but it will go on fighting. There has been an upsurge in pin-prick Isis attacks in places that has been quiet over the last year.

Mr Karim says that not only does Isis still have sanctuaries, but it can draw on a disaffected Sunni Arab population who have been displaced by the war. He points out that in Kirkuk province alone “there are 500,000 Sunni Arabs who had to leave their homes and are not being allowed to return”. Most come from Baghdad and the provinces around it from which the Sunni have been forced to flee by Shia militia, the Hashd al-Shaabi, and the Shia-dominated security forces. He said that 200,000 people who came from solidly Sunni towns and villages were being permitted to go back, but not the larger number who came from previously mixed communities of Sunni and Shia.

The great majority were displaced when Isis began a series of offensives in early 2014 which culminated in the fall of Mosul in June and brought Isis fighters to within an hour’s drive of Baghdad at the height of their success. Isis has since lost much, but by no means all, of the territory that it seized then which was largely inhabited by Sunni Arabs.

Isis terrorist tactics, and especially the thousands of suicide bombing attacks on Shia civilians, provoked sectarian hatred or at least deep suspicion directed against Sunni Arabs on the part of Shia, Yazidis and Christians that has not dissipated. These atrocities are still continuing.

“There is no reconciliation [between Sunni and Shia],” says Mr Karim and this provides fertile ground for Isis to recruit fighters. The number of these may be growing in places like Hawija and Tal Afar west of Mosul as Isis loses ground elsewhere. He adds that “the Prime Minister [Haider al-Abadi] issues directives saying that places have been liberated and their people can go home, but nothing happens.” He suggested that the motive was “to make these areas pure” or, in other words, cleansed of Sunni Arabs who might support Isis or some similar militarised Sunni fundamentalist movement.

“Mosul is a mess,” says Mr Karim, referring to the deep divisions between Sunni, Shia, Kurds, Yazidis and Shabak as well as interference by outside powers such a Turkey. Once Isis is defeated in the city, then each will demand a cut of the cake or a restoration of their previous position. “When I was student in Mosul [in the 1960s] the city was 40 per cent Kurdish, but they all had to get out,” says Mr Karim.

A problem in Iraq is that reconciliation will require reconstruction of wrecked Sunni cities and towns and this is not happening in Fallujah and Ramadi. Not only is the Iraqi government corrupt and dysfunctional, but it is very short of money because of the fall in the price of oil and the cost of the war. “It only just has enough money to pay salaries and pensions,” says Mr Karim. “There is nothing left for rebuilding. We have not received any money for this from Baghdad since 2014.”

The decision to attack Mosul first before mopping up several other areas with a strong Isis presence was largely an American one. Previously senior Iraqi officials had spoken of a slower approach. But the campaign to capture Mosul has been very much a US organised operation, though US generals have tried to give the impression that they are in a supporting role. The US also created the political conditions for an offensive, by brokering an agreement between the autonomous Kurdistan Regional Government (KRG), which has powerful military forces, and the Baghdad central government.

Baghdad and the Kurds have long been in dispute over a swathe of territory, which includes operating and potential oilfields, stretching across northern Iraq from the Syrian to the Iranian frontier. The Arab-Kurdish confrontation, which had at times come close to a shooting war prior to the rise of Isis in 2014 has hitherto been out to one side.