In Aleppo’s Mashhad neighborhood, rebels man a series of sniping positions, eyeing the government forces and their tank just 50 meters (yards) up a sniper alley from behind a short wall of sandbags. There are other tanks nearby, and when they fire the boom reverberates through otherwise quiet streets almost empty of civilians. The fighters spot a young boy carrying belongings wrapped in a blanket as he approaches the sniper alley, and call out to him. “Hey you, boy, stop right there!” one fighter shouts. The boy freezes, standing by a shouldering pile of rubbish, then dashes across the alley...