the trouble is:
Mugabe cracks down, some degree of uprising starts inside Zim - and an armed revolution starts going through its usual structure.. it means that SA and the other countries surrounding Zim, are going to be used by the resistance to Mugabe, who in turn, is going to launch 'cross border raids' back at them..
And then comes the next layer of complexity.. namely, it suits the US in some ways, to have Zim in a state of chaos - because it prevents China from getting a solid foothold in Africa. All morality issues aside, if you look at the proxy wars in other parts of this continent - they end up draining the countries economies, and removing most of the democracy that exists, while multinational corporations then quietly leech away at whatever they happen to be wanting..
So one doesn't want Mugabe to take any further steps.. because there are large superpowers who are very keen to exploit regional instability for future long term
tactical goals, and SA is right alongside the potential flash point..
This is 'interesting' at least in some ways, coz it might kick the rock over that the ANC's been hiding underneath for so many years, and show a different face to the 'democracy-loving' PR that the ANC's been riding on the coat tails of.
Because they'll have to either address the issue firmly (if total uprising/warfare erupts) or finally - side with Mugabe, and repress internal dissent in SA..