The ancient Chinese military philosopher Sun Tzu admonished his generals to "Know thy enemy." The question has always been how to do that. Too often military leaders have relied on simplistic methods for predicting the behavior of their adversaries-with disastrous results. In A Sense of the Enemy, Zachary Shore argues that successful leaders employ what he calls "strategic empathy," an ability to empathize with their opponents in order to anticipate how they will act. Wise leaders do not assume that rivals will act as they themselves would, but instead try to see into the unique internal constraints and drivers that shape an enemy's decision processes. Such leaders look not only for patterns, but more importantly for pattern breaks, those episodes when an opponent deviates from his usual behavior in a way that imposes long-term costs upon itself. They don't assume that past behavior always predicts future actions ("the continuity error") or that opponents have an unchanging character ("the fundamental attribution error"). Shore contrasts the empathic German Foreign Minister Gustav Stresemann, for example, who accurately perceived Russian intentions in the 1920s, with Stalin's repeated failure to read Hitler's behavior in the 1940s. Stalin was so blinded by ideology and paranoia that he couldn't see the Nazis' evolving strategy, and paid dearly for it. Shore insists that leaders need to be flexible, able to shift views when the facts on the ground change. Yet leaders still fail. Highlighting famous examples of successes and failures from the history of international conflict, A Sense of the Enemy sheds important new light on today's crises, from the vexed US-China relationship to the Iraq fiasco and the Iran-Israel conflict.