This article examines how the African Union (AU) has handled Africa's peace and security challenges since 2002, defines what has been successful and what remains aspirational. It does so by examining how the AU has responded, from using sanctions against coups, to deploying peacekeeping missions and mediating in conflicts. An African Peace and Security Architecture (APSA) has developed since 2002, including a Peace and Security Council, an African Standby Force, a Continental Early Warning System and a Panel of the Wise. This sounds impressive, but the operationalization record is patchy: AU-deployed missions have been fully dependent on external donors; harmonization is a major problem; serious questions remain over AU capacity; and some of the Regional Economic Communities (RECs) are developing at a quicker pace than the AU. Given these circumstances and its internal capacity deficit, the AU will likely struggle to exercise oversight of regional processes, including the development of regional standby force arrangements. APSA is clearly based on a liberal peace model, yet democratic systems, respect for human rights and good governance aren't always in place in African countries, and the self-interest of elites continues to be a constraint on APSA and its success. Over the last decade the AU has found a voice and, despite some setbacks, it has shown through AMISOM in Somalia that it is capable of conducting a successful peacemaking operation. Its biggest challenge is not making the decision to intervene or deploy forces, but the capacity of most African states to deploy effectively. APSA's dependence on external partners needs to diminish over the next decade if better African solutions are to be found to peace and security challenges in the continent. Yet, the internationalized nature of crises such as the one in Mali in 2012–13 requires international partnerships. Not all of Africa's security problems can be solved by Africa alone, but APSA does provide a vision framework for African and external partnership.