There is too much distrust amongst the AU’s membership already: Liberia, Guinea and Sierra Leone all accuse each other of backing rebel movements in their respective civil wars. The UN is asking regional organizations to shoulder some of its "peace and security" responsibilities out of desperation, as prompted by its failure in Rwanda, not as part of some strategy. In Kosovo, NATO had to intervene because Russia blocked any UN action at the Security Council. There are as yet no other successful examples of regional organizations (i.e. ASEAN, APEC, OAS) getting involved in a military conflict and successfully bringing peace.