Qayyarah, Iraq—A fighter from the coalition battling to drive the Islamic State militant group from Mosul stands guard over a neighborhood on November 10 while smoke from oil fires darkens the sky. As 90,000 coalition soldiers advance on and into Mosul, the jihadis set fire to oil wells so coalition airplanes couldn’t see targets on the ground. ISIS also posted a video online that showed four children shooting to death four people for spying, the United Nations said in a report that described other ISIS atrocities. “The extent of civilian suffering in Mosul and other [ISIS]-occupied areas in Iraq is numbing and intolerable,” the U.N. high commissioner for refugees said.