This article recounts how Neo-Scholastic international lawyers navigated the complex political landscape of the 1920s and 30s, combining universalism, nationalism and religious belief. Participating in the contemporary re-engagement of Catholics with modern politics, they re-imagined the international legal order in Catholic terms. They argued that a universal morality, overruling the extremes of state sovereignty, was the only solid basis for just and stable global legal relations. While the contribution of Catholics to the establishment of the post-war world order and the (...) rise of human rights is widely acknowledged, the interwar genealogy of these developments is not. Reading these thinkers’ universalist legal tenets in conjunction with their political trajectories provides a relevant frame to understand the moral charge characterizing international law in the early years of the Cold War. (shrink)