Families gathered around a refrigerated truck at a Syrian-Turkish border post, waiting earlier this month for the drivers to dispense their awful cargo: the bodies of 52 Syrian men, killed in a war 600 miles away. The dead were mercenaries, recruited by Turkish-backed militias in Syria to fight on behalf of Azerbaijan against Armenia, relatives said. They were deployed as shock troops, to claw back scraps of territory in the contested Nagorno-Karabakh enclave. “They went to break the borders,” said a cousin of Mahmoud Najjar, a 38-year-old Syrian fighter. The cousin, interviewed by telephone, said Najjar’s body in the cold truck was marked with the number 12. The deaths of Syrian fighters have raised alarms about how this decades-old conflict could now rapidly worsen as it draws in outside powers […]