In 2005, the United Nations (UN) committed to a “responsibility to protect” (R2P) against four mass-atrocity crimes of genocide, war crimes, crimes against humanity, and ethnic cleansing. This was a clear commitment acknowledging that states hold responsibilities to consider the protection needs of domestic, and outside, populations. However, holding actors accountable to their R2P commitments is difficult due to the politicization of the norm and the international institutions for implementing it. The result is that the UN lacks the mechanisms for promoting R2P's successful implementation, meaning R2P breaches are all too common and that there is an urgent need to find ways to hold states accountable to their pledges. Applying transitional cosmopolitanism, which calls for an incremental approach in the pursuit of cosmopolitan solutions to contemporary global challenges, this article examines an entirely new and supplementary mechanism to assist in R2P's implementation. The article calls for the creation of an “R2P Commission.” This is a suggestion for a body composed of independent elected experts to scrutinize state practice across R2P's “three pillars.” It argues that an R2P Commission would provide an effective and feasible supplementary body to enhance R2P's implementation via determinations of where manifest R2P failures have occurred, review of international practice vis-à-vis atrocity prevention and response, and recommendations for altering practice and potential response action.