S o u t h A fr ic a n I ns tit u t e o f I n t e r n ati o n a l A f f a i r s Afric a n pe rs p e ct iv e s . G lo b a l in si g h t s. Emerging Powers and Global Challenges Programme OCCASIONAL PAPER NO 91 Emerging Powers and the Changing Global Environment: Leadership, Norms and Institutions September 2011 Mzukisi Qobo