The essay traces the roots of R2P in African political thought—through individuals such as Kenya's Ali Mazrui, Ghana's Kwame Nkrumah, Tanzania's Salim Ahmed Salim, South Africa's Nelson Mandela and abo Mbeki, and Egypt's Boutros Boutros-Ghali— and considers the bid by West Africa's regional hegemon, Nigeria, to play a leadership role on the continent in relation to the norm. It argues that the regional West African giant has exhibited a 'missionary zeal' in assuming the role of a benevolent 'older brother' responsible for protecting younger siblings—whether these are Nigeria's immediate neighbours, fellow Africans, or black people in the African Diaspora. Without Nigeria's military support and economic and political clout, the ECOWAS Ceasefire Monitoring Group (ECOMOG)—which intervened in civil wars in Liberia and Sierra Leone in the 1990s—would simply not have existed. Despite the lack of a clearly agreed UN or pan-African mandate, Nigeria's interventions - under the auspices of ECOMOG - effectively operationalised R2P in the region and eventually won continental and international support. However, Nigeria's recent foreign adventures have often been launched in the face of strong domestic opposition and a failure by military and civilian regimes to apply R2P domestically. The essay concludes by considering Nigeria's need to build a stable democracy and promote effective regional integration, if it wishes to benefit from its peacekeeping successes in the region and pursue a continued leadership role in relation to R2P.