They started out in the same place -- British-founded postcolonial states in Africa, preserving the colonial system of a white minority ruling a black majority. In each case that system was overthrown. Zimbabwe became a military dictatorship with occasional anti-white pogroms officially sanctioned, and a completely dysfunctional economy. SA became a mostly stable and functional and prosperous republic whose worst problems are crime and AIDS. Whites are mostly safe in SA, though sometimes they are attacked in the rural hinterlands, but never with state complicity -- Mandela, as president, was determined to give the whites no reason to emigrate, and nobody has broken that precedent.
Why the difference?
Why the difference?