Abstract. Political instability is growing in sub-Saharan Africa. The situation has left the Sahelian countries increasingly vulnerable to insecurity resulting from armed conflicts, terrorist activities, illicit trafficking and related organized crime, ecological crisis, «resource» wars and the like. These new global and regional challenges superimposed on traditional factors, provoking conflicts (social polarization, widespread corruption, coupled with the inability of the involved governments to deliver basic services, weak administration and other). At the same time, chronic political instability is a direct result of the lack of institutionalized political dialogue, of national consensus on strategy of national security and, also, because of the continuing unwillingness of the ruling elites to engage in the development of peripheral areas. Crises in Mali and Nigeria have clearly demonstrated the «fragility» of sub-Saharan states in the face of these threats. The scale of problems in the Sahel is so great that the United Nations has proposed a new conceptual and organizational approach to their solution. Nowhere is the development–security nexus more evident than in the Sahel. Major emphasis is placed on integrated and coordinated implementation of measures in the field of security and development in the region and regional and interregional cooperation among Sahelian, West African and Maghreb states. The UN declares a top priority of “partner peacekeeping", which is based on the cooperation of the UN as the main actor with international regional organizations – the EU, AU, ECOWAS, financial institutions and donor countries as well as other bilateral partners. Currently, ensuring a coherent and mutually supportive peacekeeping of the UN and the AU becomes most urgent issue for the organizations, since the relations between them are characterized by mistrust and tension.