A recent collaboration by Sergei Goncharov, an adviser to Boris Yeltsin, and John W. Lewis and Xue Litai, both of Stanford, the book focuses mostly on the tense alliance between the Soviet and Chinese dictators. But it also sheds light on Kim, thanks to newly discovered articles and speeches by Mao, interviews with retired North Korean generals and officials, and the personal archives of Stalin’s envoy to Mao. The book debunks old speculation that America and South Korea provoked the war. Having urged unification by force since 1945, Kim “proposed it, fought for it, and with a Soviet army battle plan to guide him, executed it.” Driven by their own desires to confront the West, Stalin and Mao went along, then regretted it. If Kim bilked those tyrants, can he outwit the United States, too?