This article explores the evolving concept of international jus cogens – fundamental, overriding peremptory norms that nation-states cannot violate. It examines whether a regional set of norms can form regional jus cogens and considers its implications for international affairs. The analysis begins by defining jus cogens and identifying these norms amidst the tension between natural law theories and legal positivism. It then delves into the scope and utility of regional jus cogens, reviewing international state practices, legal precedents and doctrinal interpretations. Case studies, such as the Brezhnev Doctrine and the prohibition of juvenile executions in the Americas, illustrate the complexities of establishing regional jus cogens. The potential consequences of regional jus cogens, including increased sovereign inequality and differential treatment, are examined. The article concludes by assessing the relevance of regional jus cogens in contemporary international affairs, highlighting its potential role in promoting international cooperation and addressing regional challenges. [Winner of the Society for the Study of Social Problems’ Alfred R. Lindesmith Award]