One prominent plank of the US national creed is American exceptionalism. The roots of this imprecise but influential notion lie in John Winthrop’s portrayal of colonial America as “a city set upon a hill,” intended by God to serve as a light to the world. While this notion has obviously sparked many abuses of arrogant triumphalism, it may nevertheless retain constructive aspects. Catholic social teaching, with its call to universal social concern and even a certain cosmopolitanism of perspective, provides resources capable of salvaging the positive aspects of the double-edged sword of American exceptionalism. While recent events in US foreign policy cast considerable doubt on the ability of a hegemonic America to practice restraint and self-control, a theological evaluation of American exceptionalism, with its supposedly divinely ordained mission for service, nevertheless continues to possess constructive potential.