Conventional analyses of terrorism proscription rely on conceptions of policy in terms of bureaucratic institutions and processes functioning according to means-end rationality, and law as an institutionalised body of rules expressive of sovereign power. By contrast, this article argues that the workings of Western terrorism proscription are inseparable from and deeply conditioned by situated interpretations of the contexts and dynamics within which West-led interventions for global stability-equated with liberal order-are pursued. Predicated on a seemingly self-evident division between "liberal" conduct, actors, and practices and illiberal ones which threaten the former, the production of good order requires the strengthening of the former, and the disciplining, transformation, or destruction of the latter. However, categorisations as "liberal" or "non-liberal" are not derived from "objective" criteria, but always mutually dependent on the situated interpretations by (self-recognised) liberals of the contexts within which they are intervening. Taking an interpretive approach that treats state action as situated practice, the article traces Western states' security engagement with Sri Lanka before, during, and after the armed conflict ) to show how changing calculations for liberal peace there governed evolving proscription practices in relation to the LTTE and the Tamil diaspora.