Cohen and Zenko give a new meaning to President Franklin Roosevelt’s Depression-era slogan “The only thing we have to fear is fear itself.” Whether one looks at terrorists, rival great powers, or any other prominent threat from beyond U.S. borders, the authors maintain, the United States has little or nothing to worry about. Noncommunicable diseases kill many times as many Americans as foreign terrorists do, for example. Americans would be better off if they worried less about relatively weak enemies abroad and spent more money fighting cancer and heart disease at home. Cohen and Zenko argue that Americans’ priorities are so misplaced because of a “Threat-Industrial Complex” that hypes international dangers. Clear and Present Safety makes some effective points about the costs of ill-considered war, and as memories of World War II and the Cold War recede, it is possible that Cohen and Zenko’s reasoning will appeal to new generations of policymakers. Yet readers who can recall the consequences of the United States’ turn inward in the 1920s and 1930s will find Cohen and Zenko’s proposals disturbing; history suggests that the only foreign policy costlier and riskier than one that pursues global engagement is one that shuns it.