In an extract from his new book, James Verini gives his first-hand view of the bizarre, bleak conflict with Isis in 2016

• ‘Guilt and shame’: journalist James Verini on the US role in the destruction of Iraq

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.