We (Iraqis, Kurds and Iranians) won’t need B-52’s to get into Mosul.
ISIS is trying to dig trenches around the city (A famous tactic used by Muhammed to defend Medina), but such trenches would be a typical obstacle for Combat Engineers, with their armored bulldozers, rather than B-52’s. They will get some trenches and fighting positions developed by Summer, but we will be watching what they build. They don’t have the capability to build any kind of showstopper great wall - just hinderances that could marginally slow things or increase casualties.
No Government wants to level its own cities, and neither do the Iraqis. ISIS is a small minority in the city, even if the majority Sunni population was initially glad to see them (after a few years of Shia rule giving them the shaft). ISIS has less support from the population now, and most will likely be non-combatants.
Unless ISIS can muster a major mobilization of new fighters, it will be more like a big cordon and search operation - only blowing things up when they are firing from there, or intel pinpoints them. The main effort will be urban warfare and countering guerrillas and terrorists after occupying the city.
We’ll see how things shape up as the buildup develops - will the population rally to support ISIS, or jam the phones calling in their positions? Will ISIS reinforce or withdraw? No doubt they will deploy a bunch of suicide bombers in any case, but to really hold a big city will require sustained mid to high intensity combat. Supplying that much ammo and taking hundreds of casualties a day will test them as never before.
A lot will depend on how things are going elsewhere. If ISIS is getting coordinated major attacks on several fronts, it might abandon Mosul. If that is their only big threat at that time though, they could focus a big effort in Mosul.
And there is the possibility that the whole thing could settle into a protracted Sectarian Sunni/Shia human rights violation contest.
However it goes, I am still calling it the “Summer of Death”.
Re ISIS defenses around Mosul. My son and part of his Engineering unit accompanied Kuwaiti engineers when they crossed into Iraq and broke through sand berms and tank ditches (which were filled in with berm sand). However, this was only after the Iraqi border towers had been totally wiped out so that there would be no warnings given to Iraqi artillery/tanks etc.
These were middle level berms not the big ones like the Moroccans put up to (and did) stop POLISARIO vehicle forces from raiding Army camps (which they had done very successfully until the berms went up).
Berms and trenches in front of an enemy’s position will cost you lives that you don’t want to lose. B-52’s can obliterate massive berms and trenches in a single run without losing any good guys on the ground.
If you’ve got ‘em, use ‘em.
House to house urban fighting against a fanatical force is very costly in lives, as American and Iraqi forces found out in Fallujah I and II. I would have preferred to level small areas to wipe out snipers and bunker/houses concentrations as a demonstration to those who were left as to what was coming down the pike unless they fled or surrendered.
What I would like to know is how many ISIS troops are actually occupying Mosul (a figure I’ve never seen) and how many Sunnis are actually helping them (a figure that can only be a guessestimate).
Also, has ISIS cut off escape routes for the civilian population, thus making them hostages in their own homes?
And if ISIS does flee, how, through what road routes out of the city, and to where? If we know that, we can leave them a way out and then blast the hell out of them in the open.
A few will fight to the death so it is our duty to kill them, dead.
Standoff tactics keep your casualties down while whittling down the forces of a surrounded/entrenched enemy. A good commander doesn’t sacrifice his men in frontal attacks if there are other viable alternatives available.