What accounts for South Africa's success and Zimbabwe's failure?
Over the last couple of decades, South Africa has succeeded economically and culturally, becoming a respected member of the international community. Meanwhile, Zimbabwe has deteriorated into almost a failed state. Why is this?
It is impossible to know the answer to this with any great degree of certainty. There is no way to objectively prove what caused South Africa to be more successful.
First, I would note that it is not completely clear that South Africa will continue to succeed. In some ways, the country is not progressing. The African National Congress shows signs of becoming corrupt. Crime continues to be rampant in the country. That said, South Africa is clearly much more successful than Zimbabwe. While there is no way to know for sure why this is so, I will suggest one reason.
The reason is that post-apartheid South Africa was luckier with respect to its founding figure. After apartheid, South Africa’s first leader was Nelson Mandela. Mandela was committed to democracy and was not going to try to keep power for himself in the way that Robert Mugabe has in Zimbabwe. If South Africa’s anti-apartheid hero had been a man like Mugabe, things might be very different today. When Mugabe came to power, his ZANU-PF quickly became a very predatory organization. In particular, it took actions that drove the great majority of the white population out of the country. This was very harmful in a country that had been so dominated by the white minority. By contrast, the ANC under Mandela did not engage in such actions. They were much more committed to democracy and to the rule of law than the ZANU-PF was.
Thus, I would argue that the main reason why South Africa has been more successful than Zimbabwe is that Nelson Mandela was a much better leader and statesman than Robert Mugabe.