This article reviews western donor support for building African peace and security architecture, specifically in relation to G8 efforts to engage in the capacity-building process in line with commitments made in the joint Africa/G8 Plan to Enhance African Capabilities to Undertake Peace Operations (the joint Plan)-agreed between G8 and key African leaders at the G8 Summit in Evian in 2003. It describes a project by the New Security Issues Programme at Chatham House, carried out jointly with the Peace and Security Programme at the United Nations Association-UK and the Institute for Security Studies in Pretoria, to provide strategic input into implementing the joint Plan. The article outlines the background to western involvement in peace and security capacity-building in Africa, the nature and current status of the African peace and security architecture and some key challenges to the G8/Africa capacity-building process-particularly African institutional human resource capacity and coordination among the various players involved. Finally, it maps out potential priorities for future progress in taking the capacity-building process forward.