When students of grand strategy search the past for lessons, rarely do they look to the Byzantine Empire. Luttwak, who wrote a well-regarded history of the grand strategy of ancient Rome, thinks this is a mistake. In this exhaustive study, he shows how the rulers of the eastern half of the late Roman Empire were the true masters of the craft. Although the Byzantine Empire occupied a more vulnerable geographic position than its western counterpart, it lasted almost 1,000 years longer. Luttwak argues that the Byzantines survived by relying less on brute military power and more on allies, diplomacy, and the containment of their enemies. They were able, he claims, "to generate disproportionate power from whatever military strength could be mustered, by combining it with the art of persuasion, guided by superior information." The book makes this argument through fascinating chapters on religion and statecraft, envoys, dynastic marriages, and the Byzantine art of war, as well as through evocative details about weapons, military tactics, and taxes. Although the Byzantine Empire did not have a foreign minister, intelligence agencies, or theories of "smart power," it certainly acted as if it did.