One thing that made the battle harder is that ISIL is fighting hard, according to retired Army General Jack Keane:
Well it largely depended on ISIS. ISIS did not defend in place in Ramadi and Fallujah. They put up initial resistance, withdrew their command-and-control unit, and then eventually withdrew the main body of their forces. In Mosul, ISIS command and control is still in place, and the main body of ISIS fighters is defending in place. That, in of itself, has made the battle significantly harder. Specifically, ISIS has also used human shields to their advantage in order to disarm the American air power advantage, and they’ve done that very successfully.
I had noticed that ISIL wasn't fighting to the death in their fights for cities as early as the battle for Ramadi (and for Sinjar just before that) more than a year ago.
Which led me to wonder if the jihadis had the morale to fight for their caliphate in Iraq.
And in military briefings, there was discussion of faltering jihadi morale.
The fight did not in fact begin sooner than everyone expected and it has not moved faster than everyone expected. I was wrong in thinking that the offensive would begin sooner and go faster than the general consensus.
The jihadis are in fact fighting and dying to hold Mosul. But why?
Was jihadi morale sound all along, but the jihadis pulled back from their conquests to buy time and preserve resources for the Mosul battle?
If so, why were there reports of ISIL commanders executing their fighters who deserted rather than fight to the death? It certainly didn't sound like the lack of resistance was due to the big picture plan.
Or did the slow pace of getting on with the Mosul offensive allow ISIL to rebuild shaky morale? That is, did the delay in launching the offensive allow ISIL to rebuild their morale, which has led to the slow speed in completing the offensive?
I don't know.
Another difference is that in the past the Iraqis left an avenue of retreat open so the jihadis could flee. Now the Iraqis are more committed to isolating the defenders inside Mosul. Perhaps this has been effective in eliminating the option to withdraw.
I'll just say right now that if the jihadis are willing to die in place to fight for Mosul, we should help them die there and now.
And do read all of the interview.
And here's a Stratfor piece on the coming battle. Which is good.
My comment on their analysis is that while the harsh treatment of Sunni residents in the region by Iraqi Shia-dominated security forces opened the door to the ISIL sweep through northern Iraq in mid-2014, that harshness did not cause the defeat of the Iraqi forces trying to hold Mosul.
Our departure in 2011 gave the Shia-dominated government the freedom to let corruption erode the security forces by decimating the leadership by replacing trained soldiers with politically loyal leaders who lost the confidence of their troops. Good troops could have withstood the ISIL and local Sunni uprising without collapsing. The Iraqis would have lost ground, but not suffered such a complete defeat.
Anyway, I just don't know if the ISIL defenders will continue to fight as hard as they did for the east.