In 1983, the American Catholic bishops’ conference released The Challenge of Peace , a pastoral letter on nuclear weapons policy. This article examines the drafting process of that pastoral letter, revealing a complex relationship between President Ronald Reagan, Pope John Paul II, and the U.S. bishops. At the same time Reagan was strengthening the relationship between Washington and the Vatican, the American bishops were becoming increasingly critical of the president and his policies in a way not previously seen from the Catholic hierarchy—a tension that colored the drafting of The Challenge of Peace . The pastoral represents a watershed moment in the transformation of the American Catholic Church into a major voice in the American public sphere.