In Hit — a small town to the west of Ramadi retaken from IS in April — Iraqi commanders complained that it was becoming increasingly difficult to get requests for airstrikes cleared by coalition forces. Brig. Gen. Sami Khathan al-Aradi said progress in Hit was slower because of the reduced airstrikes.

“Our allies have their own standards, their own regulations,” al-Aradi explained, implying that Iraqi planes would have used airstrikes more liberally.

Mosul is roughly two-thirds larger in area than Ramadi, and some 1 million to 1.5 million residents are still in the city — a far higher number than those who were in Ramadi as Iraqi forces fought to regain it — putting large numbers in harm’s way when an assault is launched.

The destruction of Mosul on the same scale as Ramadi would result not just in billions of dollars of damage. It also would risk further alienating the Sunni minority population. Long oppressed under the Shiite-led central government in Baghdad, some Sunnis originally welcomed IS fighters into Mosul and parts of Anbar province. But after months of increasingly brutal IS rule, the group’s support among Sunnis appears to have eroded.

Widespread destruction also can spark cycles of revenge attacks within Anbar’s communities, where tribal law often demands death and destruction be repaid in “blood money.” In Ramadi’s eastern edge, local security officials have already begun methodically razing homes of suspected IS sympathizers.

Hamdiya Mahmoud’s family home was destroyed by IS militants. Amid the rubble that was once her son’s bedroom, she points to a dresser showered with shards of plaster and concrete that was a gift to her son and his wife on their wedding day.

“I didn’t let my youngest son go to school to save money to build this house,” Mahmoud said, breaking into sobs, “This house is really priceless to me, it’s like one of my sons.” Mahmoud said she would not seek revenge for the damage done to the property. But as her husband looked over the ruins of his house, he was less forgiving.

“I swear to God,” said Ali Hussein Jassim, “if I learn who did this I will not keep silent.”