News of Abdul Niazi’s death arrived in a chilling phone call. It was March 26, nearly the end of Ramadan, and his wife wanted to know when to expect her husband, a former U.S. military interpreter who lost both legs in a bomb blast in Afghanistan and became one of Houston’s most well-known advocates for new Afghan migrants. It was almost time to break the day’s fast, recalled Niazi’s cousin, but he hadn’t returned home. So she called his cellphone. “I’m not your husband,” the man on the other end of the line said, according to Rizwanullah Niazi, Niazi’s cousin....