By Paul Rogers, The Conversation From Business Insider

Iraqi government forces are closing in on the historic Grand Mosque in Mosul, close to the heart of the old city, which remains in the grasp of Islamic State (IS).

Iraqi helicopter gunships are in action, as arecombat aircraft from coalition forces and the Iraqi Army hopes to gain control of the mosque imminently.

This would be a huge symbolic blow to IS. It was in the Grand Mosque that the group’s leader, Abu Bakr al-Baghdadi, announced the new “caliphate” in July 2014.

He spoke at the first Friday prayers of Ramadan and it marked the start of the peak period of power for IS as it took control of much of north-western Iraq. Since then, though, the intense US-led air war has killed over 50,000 IS supporters, the expansion of the movement has stalled, and the Iraqi Army has retaken substantial territory.

So is the looming loss of the Grand Mosque the beginning of the end for IS – or is it just another turning point in a long drawn-out war?

The operation to retake Mosul started in October 2016. Iraqi forces and their allies stormed towards eastern Mosul so quickly that some predicted the whole of the city would be controlled by the Iraqi government by the year’s end. But the offensive soon met a stalemate, and it was three months before the Iraqi Army reached the banks of the Tigris, which divides eastern from western Mosul.

After a month’s pause, the assault began on the west of the city and its Grand Mosque. But by then, the elite Iraqi Counter Terror Service (orGolden Division) had sustained serious casualties and there were already fears that Mosul would turn out to be a pyrrhic victory, reducing the one force that the Iraqi government could depend on in any future civil war to a shadow of its former self.

As in eastern Mosul, progress was initially rapid but then descended to a bitter war of attrition, especially as Iraqi forces got closer to the densely packed old city. IS’s defensive forces are determined to maximize Iraqi military casualties; in one recent attack, IS used an armored bulldozer to force its way through a road block before detonating a bomb. The Iraqis in turn are using air power and artillery much more readily, as happened in the new assault on the Grand Mosque, which has led to a sharp rise in civilian casualties.

Meanwhile, Iraqi and US government sources have offered different assessments of progress: while Iraq said that nearly 60% of western Mosul had been retaken, the US commander, General Joseph Martin, put it at “a little over a third”. But whatever the truth, the battle for western Mosul is repeating many of the features of the closing stages of the earlier battle for eastern Mosul, with heavy casualties among Iraq’s elite forces and even higher civilian casualties.

Down, but not out

IS is preparing for a rather different future. Just as it comes under intense pressure in Mosul, it is unexpectedly opening up new fronts in other parts of Iraq. There are reports of a surge in IS raids around Baiji and Tikrit, both well south of Mosul towards Baghdad. The Baiji police chief reported that until a few weeks ago, IS attacks were rare, but that there have been40 in the last month alone.

Clearly the group is far from finished in Iraq. The indications are that it has already started the process of going underground, shifting from controlling territory to guerrilla warfare. It will be supported by many Sunnis who’ve seen the high number of civilian casualties caused by Iraqi government forces. The state is now highly dependent on Shia militias and Iranian Revolutionary Guard Corps units – both of whom Iraqi Sunnis view with great suspicion.