Yan takes on a classic question: Why do great powers rise and fall? With an eye to explaining recent Chinese success in challenging U.S. dominance, he advances a theory he calls “moral realism.” Borrowing from ancient Chinese philosophers, Yan argues that when governments define a moral worldview, they are more likely to successfully take over from their declining peers. Much of the book details how states can project moral strength in world affairs, which, for Yan, means offering sober and consistent definitions of the national interest, protecting international norms, and establishing credibility in alliances. Yan argues that since the end of the Cold War, China has been more successful—or “efficient”—in this project than the United States and thus has steadily gained ground on its rival, although he admits that China has yet to develop a set of postliberal values that can compete for global influence. It’s not entirely clear whether Yan’s theory is distinctively Chinese, but he is surely correct that U.S.-Chinese competition will turn not just on hard power but also on each country’s ability to command the moral high ground.