An important book on the roots of war, remarkable in its theoretical rigor and historical sweep. Van Evera demolishes the view that war is an inevitable outgrowth of an anarchic world that encourages belligerence. In fact, waging war on others rarely makes sense -- because aggressors are more often punished than rewarded. Van Evera finds the best explanations for war in the misperceptions that stem from shifting power relationships. Most of the great wars of the modern era resulted from leaders miscalculating their prospects for victory. The assumptions behind attempting a preventive war or securing easy conquest are in fact often disastrous. States are rarely as insecure as they think they are, and trying to reduce their perceived insecurity only makes them worse off. If modern war is indeed based on such fallacies, the good news is that greater transparency and knowledge can at least partly overcome ill-considered thinking. The bad news is gauging perceptions remains a murky business. The missteps of statesmen often reflect national insecurities and ambitions deeply rooted in culture and history. The book convincingly argues that understanding the causes of war requires knowing why states misjudge the structure of power. Alas, Van Evera leaves unanswered how we can overcome this challenge.