International organizations have played a critical role in promoting international peace and security since the end of the Second World War. The rise of the Intergovernmental Authority on Development (IGAD) from a development forum to an active mediator in peace and conflict resolution provides a unique example to examine the involvement of regional actors in international peacebuilding. Africa has been struggling with different forms of conflict for over half a century, and the input from international actors has elicited mixed reactions. Prior to the outbreak of countrywide fighting from December 2013, a United Nation (UN) peacekeeping mission was already underway in South Sudan. The Intergovernmental Authority on Development (IGAD) has increasingly become a critical component in Eastern Africa’s integration efforts. The Nairobi Summit paved the way for the mediation process to commence, and after three weeks of negotiations in Addis Ababa, an Agreement on the Secession of Hostilities was signed on 24 January 2014.