Karin Tanabe’s moving new book, “The Diplomat’s Daughter,” is set during the global turmoil of the late 1930s and ’40s, but its political resonance is classic and its story is attractive. On a hot day that is white , boys play soccer in a World War II-era internment camp in Texas’ walls. Fellow captive Emi Kato finds out how “un-Japanese” the boys look: It shocked Emi to believe that the American government believed these fenced-in kids dangerous. Not long after, as starvation and disease steal tens of thousands of lives he and his parents flee the Nazis and settle in Shanghai, in which they are held by the Western in a ghetto. Tanabe’s descriptions of how these men and women endure the physical and emotional suffering of war is riveting.