This chapter explores the evolving relationship between WPS and the Responsibility to Protect (R2P). It begins by outlining the emergence of R2P in the wake of failures to respond adequately to mass atrocities in Rwanda, Bosnia, and elsewhere, and evaluating the charge that, as originally conceived, R2P was “gender blind.” The chapter moves on to show how the UN Secretary-General and others have attempted to build bridges between the two agendas and how the Security Council has looked to simultaneously implement both. This section also considers some of the feminist critiques of R2P in light of these efforts. The third part of the chapter sets out the similarities and differences between the two agendas and calls for greater cross-fertilization between them, including through the incorporation of a gender lens into atrocity prevention and an atrocity-prevention lens into WPS. Overall, the chapter argues that the two agendas should be understood as mutually reinforcing, such that the attainment of one requires the attainment of the other, but that they are complementary rather than synonymous agendas inasmuch as they contain important differences.