By Michael Cruickshank, @MJ_Cruickshank
Despite early successes, the operation to retake Mosul from ISIS is now encountering serious resistance.
Recent attacks spearheaded by the Iraqi Army into the eastern outlying suburbs of Mosul have faced sustained ambushes and static defence by ISIS fighters causing numerous casualties.
While official figures from the Iraqi Army on the number of deaths that they have incurred over the last 72 hours are not yet available, reports from journalists embedded on the front line paint a picture of intense urban combat.
In one particularly remarkable report, CNN journalist Arwa Damon entered Mosul with a long column of Iraqi Army troops before being ambushed and having almost all of their vehicles immobilized or destroyed.
A combination of suicide car bomb (SVBIED) attacks, combined with accurate sniper, rocket and mortar fire turned the narrow streets of the city into a deathtrap. After the Iraqis were forced to retreat with many wounded, ISIS released propaganda footage of a street filled with at least 10 destroyed Humvee and MRAP vehicles.
Despite this setback the attack has continued, with new Iraqi forces pushing into eastern Mosul, while Peshmerga troops took the strategic town of Bashiqa yesterday.
Nonetheless, what can be seen is that ISIS is choosing to stand and fight in Mosul, with its estimated 5000-6000 fighters, many of whom are suicidal fanatics.
Beyond their usual tactics of IED minefields and suicide bombings, ISIS is now copying from other guerrilla warfare specialists throughout history – such as the Viet Cong – and building vast tunnel networks between their positions.
Advancing Peshmerga and Iraqi Army troops have reported ISIS fighters enjoy tactical mobility and the element of surprise through the use of these tunnels, and can emerge behind lines to harass and ambush troops, often with deadly results. Moreover ISIS is also applying scorched earth tactics, destroying infrastructure and chemical storage facilities in order to further slow the advance into Mosul.
Taken together, these developments show that ISIS is putting up the kind of determined resistance that many analysts had feared prior to the beginning of the operation.
While ISIS is cut off, heavily outnumbered and bound to eventually lose the city, this battle could now take months, and civilian casualties could be extensive. Barring any major change of strategy, the Islamic State’s final stand in Iraq could be its most deadly by far.