This groundbreaking book offers a comprehensive analysis of the United Nations' efforts to incorporate the Women, Peace, and Security (WPS) agenda into its mediation practices. Based on extensive fieldwork and primary material, the book examines how gendered and racialised ideas about mediation as an 'art' or a 'science' have shaped the UN's approach to WPS. Senior mediators view mediation as an art of managing relationships with mostly male negotiators, meaning that including women can threaten parties' consent to the process. Meanwhile, experts and headquarters units see mediation as a science, resulting in the co-optation of gender expertise and local women to reinforce technical approaches to mediation. This has hindered the WPS agenda's goal of meaningful women's participation in peace processes. This book is an essential read for scholars, policymakers, and practitioners interested in gender, peace, and security.