As the Iraqi-led coalition move to liberate Mosul, Iraq's second city, the question we should all be asking is this: What will happen next?

What will be the outcome, the ramifications and legacy of the capture of the city, its occupation, the symbolism of its liberation and finally, its recovery?

Coming from Northern Ireland, I know that the siege of Londonderry is still recalled in detail 300 years after it ended. It remains a point of contention because of its religious significance. Will Mosul be the same? Possibly.
The once multi-faith and ethnically diverse Mosul has changed; the sectarian balance has shifted in favour of Sunni Muslims, especially after the expulsion of the Kurdish and significant Turkoman population -- and the obliteration of the Christians, Jews, Yazidis and Manadeans.

Mosul will never be the same again in terms of population or its ancient treasures. Even the ancient tomb of the Prophet Jonah was demolished.

The once multi-faith and ethnically diverse Mosul has changed; the sectarian balance has shifted in favour of Sunni Muslims, especially after the expulsion of the Kurdish and significant Turkoman population -- and the obliteration of the Christians, Jews, Yazidis and Manadeans.

Mosul will never be the same again in terms of population or its ancient treasures. Even the ancient tomb of the Prophet Jonah was demolished.

Facing them will be the Iraqi Army: not former Iraqi Prime Minister Nouri al-Maliki's rabble, who ran away without firing a shot in defence of Mosul in June 2014, gifting the most modern weapons and equipment to both ISIS and Kurds. It is now a (pulled together all too quickly) force revamped with US and UK coalition trainers -- and with modern Russian weapons and armour.

Bolstered by successes in Anbar, they are experienced at least. They will be joined by a coalition of Kurdish forces, some: like the Zeravani -- special units under the previous Irbil administration -- and other Turkish-trained and backed units.

To these will be added, as required, the Shia popular militias -- gangs drawn from Iraq's southern regions, hell-bent on revenge for the massacres of 2014.

Quite a collective. Watching, planning, guiding and goading will be Maj. Gen. Qasem Soleimani of the Iranian Revolutionary Guards Corps Qods Force. He is the kingpin, and potential winner here.

What is certain is that it will be messy. I recall the US Marine's investment of Falluja in 2004. I served there with the Marines in 2008. That was a slog.

One is also mindful of the unfortunate events surrounding the fall to the Iraqi army of Tikrit, Ramadi and Falluja. ISIS propagandists have left the population in no doubt of what happened. Expect to see the population used at once as human shields for defence, then as chaff to disguise fighters slipping away in the tide of human misery, and then a whipping boy for the frustrated militias when they fail to grasp the elusive ISIS -- which they have been promised -- and turn on the helpless Sunnis left behind.

I really hope it is a quick and decisive military operation with a disciplined command structure, which will be generous and magnanimous to the terrified population. I hope it is not an orgy of death followed by vengeance.

The problem is, ISIS probably wants exactly that to happen. It is what they are praying for. The popular militias do, also.

A descent into further conflict would also suit the Turks and their Kurdish proxies, who have a score to settle.

The Iranians would like to see this challenge to their influences across Iraq destroyed. The Syrians would like to see rebellious Sunnis taught a lesson, (their Russian allies just want them to be happy) and the Iraqi Army wants to restore its pride.

Should we in the West be just content that a significant part of ISIS falls? Well, it is only part of the physical state. It will only encourage those who have established "Villayats" -- statelets of ISIS in Libya, Afghanistan, Indonesia, Philippines and elsewhere. It will also play well as a recruiting call to arms for the worldwide virtual Islamic state -- present everywhere.

As the Protestants of Ireland still celebrate the siege of Derry today, let's hope the events of the next few weeks do not write a narrative for the next 300 years in Mosul.