The use of force is prohibited under international law. There are, however, exceptions to this rule. The most important is that of self-defence as enshrined in article 51 of the Charter of the United Nations. There are also military sanctions imposed by the Security Council under Chapter VII of the Charter, the implementation of which is subject to control by the Council. In addition to operations to implement military sanctions, peace operations should also be included. Those deployed on the basis of Chapter VI, for the implementation of peace agreements, have a limited right to the use of force in situations of self-defence. Other operations (most of those authorized by the Security Council on the basis of Chapter VII since 1999) have the right to use force to protect civilians. Finally, more recently, another exception to the rule of the prohibition of the use of force has been formulated through the responsibility to protect populations at risk of mass atrocities (genocide, war crimes, crimes against humanity and ethnic cleansing). The rule of the prohibition of the use of force and the above-mentioned exceptions are also applicable in the African context. This chapter will examine African practice in this area in order to assess whether there is regionalism. The implementation of jus ad bellum in the African context will be studied in the light of the practice of these two African Regional Organizations and its implications for international law will be assessed.