Brands and Edel belong to a new generation of American foreign policy thinkers and practitioners. Most of this generation begins its analysis with the failure of the United States to create the stable, peaceful, and democratic world order that presidents from George H. W. Bush to Barack Obama tried to build. Many react to that failure by embracing some form of retrenchment. Brands and Edel, in contrast, worry about what the world would look like if the United States pulled back. For them, U.S. foreign policy should be less about building utopia than about preventing disaster. World order is a fragile thing, human nature is as flawed as it has always been, and the abyss is never far away. China, Iran, and Russia, they argue, are not merely geopolitical nuisances. They are attacking the values and institutions of open societies with all the tools of the information age. Unless met with resolute American power guided by wise strategies, they will return the world to an age of catastrophic war. This is an unfashionable message, but Brands and Edel have a lot of history on their side. Having squandered so many of the opportunities presented by the end of the Cold War, the United States must now contend with a harsher world, under a darkening sky.