Reviewing "The Rape of Nanking" in The New York Times Book Review, Orville Schell called it an "important new book," adding that Ms. Chang "recounts the grisly massacre with understandable outrage."

She had a keen personal interest in the subject. Ms. Chang's grandparents had fled Nanking just before the occupation, eventually settling in the United States. Growing up in the Midwest, she heard family stories of the massacre, but as an adult she was unable to find much about it in print. In China and Japan, and even in the West, the subject had been almost completely lost to history.

"The whole issue had scar tissue growing over it, but it had never really healed," Mr. Schell, the dean of the Graduate School of Journalism at the University of California, Berkeley, and a longtime observer of China, said in a telephone interview. "She sort of threw the curtain back on a period that the Chinese Communist Party and the Japanese hoped was shrouded in official declarations of a new collaboration. But it turned out there was a lot of unfinished business."

Fluent in Mandarin, Ms. Chang traveled to China, where she scoured archives and interviewed elderly survivors. What she learned would force her to describe the indescribable:

"Many soldiers went beyond rape to disembowel women, slice off their breasts, nail them alive to walls," Ms. Chang wrote. "Fathers were forced to rape their daughters, and sons their mothers, as other family members watched. Not only did live burials, castration, the carving of organs and the roasting of people become routine, but more diabolical tortures were practiced, such as hanging people by their tongues on iron hooks or burying people to their waists and watching them torn apart by German shepherds. So sickening was the spectacle that even Nazis in the city were horrified."

"The Rape of Nanking" spent 10 weeks on the New York Times best-seller list, and close to half a million copies have been sold, Ms. Rabiner said.