In Mosul, it was obvious, the jihadists would make their grand last stand. Smaller fights would follow, but this would be the showstopper. It would be not just the biggest and most devastating battle of this war, but the biggest battle, in a sense the culminating battle, of what was once known as the war on terror. When it was only half done, a Pentagon spokesman would call the fighting in Mosul “the most significant urban combat since WWII”. I was in Mosul when I read that. I had gone to Iraq for the first time in the summer of 2016, to write about life in the Islamic State’s wake. I got a month-long visa. I ended up staying the better part of a year.

Every CTS [Iraqi Counter Terrorism Service] position I saw in Mosul was as insecure as the one in Zahra [in the east of the city]. No checkpoints, no regular sentries, sometimes not even a perimeter. Locals wandered in and out. The soldiers were usually obliging. Near the triage station in Gogjali, on a slope overlooking east Mosul, was a nascent neighbourhood, a scattering of freestanding structures, half-finished homes, cinderblock foundations. Some were inhabited by their owners or refugees, others abandoned. One of the latter, a modest one-storey house that once aspired to two storeys, had held enemy fighters or served as a stopping place for them as they tried to escape the city. On the cement floor of the small courtyard was a discarded Rhodesian ammunition chest rig and by that, in a sink, a pile of hair of what had once been a beard. Occasionally you came upon just such perfect tableaux.

CTS had moved in. To my untrained eye, this at first appeared to be just another command post in a requisitioned home like the one in Zahra. Someone better versed than myself in the instruments of high-tech warfare would have understood the significance of the large aerials on the roof and on the APC [armoured personnel carrier] idling in front. What I noticed was that, on the ground floor, the soldiers who sat on the overstuffed wall-to-wall sofa smoking and drinking tea and studying their phones, as they would have done in any command post, were also shooting covetous glances at the stairwell, on which they were not permitted. It wasn’t until I ascended the stairs that I saw why this was: on what would have been the second level, and was now instead a kind of terrace, was the coalition’s forward air command. From here the air war on Mosul was being directed.

It was a sparse and alarmingly vulnerable affair. To the south, the terrace was blocked from view by a wall, the only wall. The rest was surrounded by a waist-high parapet, meaning it was exposed on three sides. From a decent vantage to the north or west or east, you could have monitored it, or shot at it, or shelled it. There didn’t appear to be such a vantage, but then there didn’t appear to be much of anything, so filled was the air with smoke and dust. That the place was never blown up by the jihadists seems a miracle.