While war between the United States and China is a possibility, a larger and more refined lesson could be gleaned from Thucydides’ ancient text. In an era of great power competition, The Peloponnesian War provides one of the first nearly complete histories of a conflict that included complex alliances, ideologically opposing views, civil discord, diplomacy, total war, and human struggle. It provides examples of how the choices made by Athenian and Spartan leaders mattered in determining whether they avoided war or led their countries into conflict. Most importantly, The Peloponnesian War offers strategists and policymakers invaluable insights into the nature and character of competition between two great powers and makes clear the importance of strategic options that avoid ill-conceived conflict.