At the 2005 World Summit, the world‘s leaders committed themselves to the “responsibility to protect”, recognizing both that all states have a responsibility to protect their citizens from genocide, war crimes, ethnic cleansing and crimes against humanity and that the UN should help states to discharge this responsibility using either peaceful means or enforcement action. This declaration ostensibly marks an important milestone in the relationship between sovereignty and human rights but its critics argue that it will make little difference in practice to the world’s most threatened people. The purpose of this article is to ask how consensus was reached on the responsibility to protect, given continuing hostility to humanitarian intervention expressed by many (if not most) of the world‘s states and whether the consensus will contribute to avoiding future Kosovos (cases where the Security Council is deadlocked in the face of a humanitarian crises) and future Rwandas (cases where states lack the political will to intervene). It suggests that four key factors contributed to the consensus: pressure from proponents of the International Commission on Intervention and State Sovereignty, its adoption by Kofi Annan and the UN’s High Level Panel, an emerging consensus in the African Union, and the American position. Whilst these four factors contributed to consensus, each altered the meaning of the responsibility to protect in important ways, creating a doctrine that many states can sign up to but that does little to prevent future Kosovos and Rwandas and may actually inhibit attempts to build a consensus around intervention in future cases.