What is the theme in The Rape of Nanking by Iris Chang?

Nationalism/Japanese identity is the major theme in the book. Throughout the novel, Chang places at least some of the blame for the events at Nanking on the development of nationalist and the Japanese identity, making it one of the primary themes of the novel. According to Chang, the identity of the people stems from ancient warriors known as samurai, who believed that to die for their lord was to die with honor. Additionally, the isolation of the country as a whole, beginning with the rule of the Tokugawa clan in the late fifteenth century, also helped shape the nation.