Since ancient times, there have been military operations that attempted to produce tectonic shifts in the balance of power. In this volume, historians demonstrate how knowledge of past military operations can inform current policy discussions by analyzing conflicts between dominant states and the rising powers who seeks to contest their hegemony. What might a conflict between the United States and its main rival, China, look like in the years ahead? What factors are important for strategists to consider? Paul A. Rahe considers the rival ambitions between Sparta and Athens. Barry Strauss explores the Punic Wars fought by Carthage and Rome. Edward N. Luttwak examines a decisive military campaign between the Byzantine empire and its nemesis, the Sasanians. Peter R. Mansoor describes the emergence of Sweden as a military might under the leadership of Gustavus Adolphus. Andrew Roberts studies the expansion of French power during Napoleon's Italian campaign. Michael R. Auslin formulates a hypothetical conflict between China and the United States in the year 2025. Each of these conflicts offers important lessons about the behaviors of ascendant powers and the responses they provoke.