MOSUL (Iraq) • Sitting in a room in a burnt-out house here in 2017, a group of Iraqi Special Operations Forces soldiers and I watched with surprise as two Islamic State in Iraq and Syria (ISIS) fighters appeared on the live video feed of a security camera. The two fighters were preparing to fire a rocket-propelled grenade in our direction. But instead of the usual bearded men with long hair, the fighters, clad in black abayas and niqabs, appeared to be women.

As it has lost power and land over the past year and a half or so, ISIS has quietly shifted from insistence on a strict gender hierarchy to allowing, even celebrating, female participation in military roles.