Prevention is a central pillar of the ‘Women, Peace and Security’ agenda, a policy architecture governing gender and conflict that is anchored in a suite of United Nations Security Council resolutions adopted under the title of ‘Women and Peace and Security’. In this article, I argue that prevention is currently constituted within the WPS agenda in multiple ways, all of which are organised in accordance with different logics: a logic of peace; a logic of militarism; and a logic of security. This presents prevention as a paradox, because in operation it collapses back into a logic of security, even as it is constructed and positioned as security's temporal and conceptual other. I provide a close reading of the WPS resolutions and show how the articulations of prevention across the agenda, and in certain resolutions, operate according to logics of security and militarism. The significance of such an argument is twofold: it lies both in the possibility of reconstruction of prevention in the WPS agenda according to different logics, and in the potential of undoing security – as the manifestation of prevention in practice – in queer, feminist, decolonial, and posthuman ways of knowing and encountering the world.