Recent decades have witnessed great interest in Leon Trotsky’s idea of uneven and combined development (UCD) by Marxist scholars of International Relations (IR). A burgeoning literature has argued that one interpretation, Justin Rosenberg’s U&CD, resolves the question of ‘the international’ by offering a single, non-Realist theory capable of uniting both sociological and geopolitical factors in the explanation of social change across history. Evaluating this claim, this paper argues that the transhistorical ways in which U&CD has been developed reproduce, reaffirm and reinforce some of the more important shortcomings of Realist IR. I develop my argument through an internal critique of Rosenberg’s conception of U&CD, which, I argue, is illustrative of larger shortcomings within the literature. I conclude that the political and geopolitical economy of UCD and their dynamics must be grasped through the specific social and historical relations in which they are immersed.