The institute has already drawn criticism from the right and left. The militarist Senator Tom Cotton, borrowing the language of the internationalists discussed in Tomorrow, the World, has labeled Quincy “an isolationist blame America first money pit for so-called ‘scholars.’” For their part, some on the left have worried that the organization’s “reformist perspective,” to quote a Jacobin article, is not sufficiently radical to offer a genuine alternative to American Empire. There are also many groups—such as defense contractors—that don’t want to see the United States restrain its military power. In 2019, the defense industry spent about $112,500,000 on lobbying, which likely encouraged Congress to recently vote against reducing the defense budget by a modest 10 percent. U.S. primacy in 2020 is much more than an ideal or assumption. It is the organizing principle for very influential and wealthy interests that will not be easily defeated.

Although a vast architecture provides material and ideological support for American primacy, there are signs that public support for it is attenuating. A Pew poll last year discovered that almost half of adults under 30 believe it would be acceptable for another country to develop military capabilities equal to those of the United States. That same poll also determined that 73 percent of Americans believe diplomacy is the best way to ensure peace, while a poll funded by the Charles Koch Institute similarly found that around three-quarters of those surveyed want to bring the troops home from Afghanistan and Iraq. During his campaign for the presidency, Bernie Sanders promoted a restraint-oriented foreign policy that was enthusiastically embraced by his supporters. And with the Quincy Institute, heterodox analysts of foreign affairs finally have a home.

Wertheim’s book contributes to the effort to transform U.S. foreign policy by giving pro-restraint Americans a usable past. Though Tomorrow, the World is not a polemic, its implications are invigorating. Americans, Wertheim argues, are not forced to exert power, helpless to do anything but dominate. The popular notion that global “leadership” was foisted unwittingly upon a nation that wanted to remain aloof from foreign military affairs but, for the good of the world, decided otherwise is a fairy tale. By demolishing this convenient and flattering myth, Wertheim opens space for Americans to reexamine their own history and ask themselves whether primacy has ever really met their interests.

For decades, the political establishment refused to present Americans with the choice as to whether they should rule the world. There was simply no alternative to armed primacy. If the failures of post–Cold War U.S. foreign policy—the disasters of Afghanistan, Iraq, and Libya; the illegal assassinations; the siphoning of resources from butter to guns—have revealed the devastating limits of power, they have finally made restraint thinkable.