This chapter examines Cold War liberals’ role in a campaign against “slave labor” in the Soviet Union between 1947 and 1953 that was largely conducted at the United Nations. Although the effort was first spearheaded by the American Federation of Labor, U.S. liberals eventually joined forces with an ideologically diverse set of European actors, and the transatlantic dialogue that ensued offers an opportunity to examine what was distinctive about liberal opposition to Soviet forced labor practices. The chapter argues that, although scholars have long emphasized Cold War liberals’ minimalist orientation toward avoiding cruelty, in comparative terms American liberals stressed the suffering of Soviet gulag victims much less than did their non-liberal continental counterparts. Instead, U.S. liberals offered a highly abstract and legalistic defense of negative liberties, drawing on a selected canon of classical economic arguments for freely contracted labor and a set of civil libertarian principles concerning freedom of opinion. Moreover, after 1951 they seamlessly shifted into different registers as these themes became politically inconvenient. In the end, antipathy to the Soviet regime, rather than a coherent and consistent set of liberal beliefs about either cruelty or the value of workers’ liberty, was the common thread running through Cold War liberals’ “fight for free labor.”