Abstract: While global consensus on the meaning and application of the responsibility to protect (R2P) principle remains tenuous, there is little contention among major actors that the development of the norm should prioritise the prevention of mass atrocities. In particular, BRICS countries, whose role is vital for the future development of R2P as a global norm, but which continue to express reservations about the intent and application of the doctrine, have been strong advocates of the preventive aspects of the principle. This rhetorical consensus, however, belies the conceptual and practical challenges that are associated with the prevention of mass atrocities. In this paper, I use the example of South Africa’s post-conflict reconstruction and development (PCRD) interventions in South Sudan from 2005 to 2013 to reflect on the role of external actors in supporting conflict-affected states to implement the preventive aspects of R2P. I argue that while South Africa, like other BRICS countries, has used the rhetoric that atrocity prevention should be at the core of R2P to legitimise its opposition to military intervention for humanitarian purposes, it has struggled to back this rhetoric with coherent strategies and concrete actions to prevent mass atrocity crimes within its sphere of influence. The gap between rhetoric and practice in the preventive aspects of R2P is not unique to South Africa, but highlights fundamental difficulties inherent in global efforts to prevent mass atrocities.