Dang Chi Trung and his sister, Dang Chi Tam, live in a small house that once belonged to their parents. The children of lifelong Communist Party members who fought against the French in the 1950s and the Americans a decade later, they live on a government allowance of about $60 a month. Both parents are deceased, leaving Dang Chi Trung, 44, to care for his sister, who’s 43. She’s mentally disabled because of her parents’ exposure to Agent Orange during the Vietnam War. She is completely dependent on her brother.