Americans stationed in occupied Japan at the close of World War II claimed to be bringing religious freedom to a country where it did not exist. They described Japan’s 1889 constitutional guarantee of religious freedom as a fake, and they claimed to be implanting “real religious freedom” in its stead. But in making such claims, the occupiers overlooked inconvenient historical facts. Countering the victors’ narrative, Jolyon Baraka Thomas shows that Japanese people were actually involved in a robust debate about religious liberty for decades before the occupation began; he also demonstrates that the American occupiers were far less certain about how to define and protect religious freedom than their triumphalist rhetoric suggested. And whereas post-occupation histories have commonly assumed that the occupiers introduced the human right of religious freedom to Japan, Thomas argues that the inherently transnational circumstances of military occupation prompted a new conception of religious-freedom-as-human-right: timeless, universal, and innate. Along the way, the occupiers and their Japanese counterparts collaboratively constructed a new technical vocabulary about “good” and “bad” religion. The categories they developed in the late 1940s still dictate how academics, journalists, and policymakers working today imagine who deserves religious freedom, what kinds of political practices infringe on religious liberty, and who bears responsibility for doing anything about it.