Uneven and Combined Development (UCD) is a social theory of the international. Originating in the writings of Leon Trotsky, most explicitly in the opening chapter of Trotsky's The History of the Russian Revolution (1932), scholars of UCD aim to expand on what Trotsky never fully formulated. First introduced into the discipline of IR at the 1995 Deutscher Memorial Lecture by Prof. Justin Rosenberg (University of Sussex), UCD has gained considerable attention both in IR and Historical Sociology. In this episode Justin Rosenberg is in conversation with Judith Koch (University of Sussex). Among other things, they talk about UCD's contemporary applications and critiques as well as new directions in UCD research, including ecology, literary theory, and science fiction.