According to supporters of R2P the principle now enjoys almost universal acceptance and the remaining challenges concern operationalization and implementation. In contrast, this article argues that R2P remains controversial both as a principle and in terms of its application, and these controversies reflect broader tensions in international politics related to international order and normative authority. Diplomatic debates related to R2P suggest that rising powers are resistant to aspects of the normative ‘rules of the game’, and that there are fundamental disagreements regarding the relationship between human rights and international order. This can be understood as a tension between pluralist and solidarist worldviews, but also a manifestation of friction regarding control of international institutions and decision-making. Although R2P is defined narrowly, therefore, this article argues that the controversies surrounding the principle must be understood within a wider political context. In conclusion, the article offers a number of suggestions as to the future of R2P based upon this analysis.