Ok, so you say that the people in South Africa made there bed and now they must lay in it? Hehehe thats so funny. As soon as Mandella took office things went to cheese!
If you remember, I said its a thought some people have. I personally think some responsibility must lie with the white folks of South Africa for the situation they are in now. For decades they lived an affluent life-style, based on the open and deliberate oppression of a racial MAJORITY. What did you expect to happen when Apartheid ended? A Martin Luther King type of eden to be created, where the children of slaves and former slave owners would skip happily, hand in hand, into the African sunset? Come on...
You criticize the Mandela government - what is the alternative; would you prefer a return to apartheid? Perhaps then you wouldn't have to be confronted by the legacy of such an horrific regime.
So you think sitting back and doing nothing will solve the problem? You think that the oppressed will rise up and overthrow their tyrant oppressors? How much time are you willing to give - 10 years? 50? 100? And meanwhile people starve, die of easily preventable diseases while they pay off ridiculous debts to us. It won't be they who will get the wake-up call, it will be us in a 100 years time, when a whole continent knocks at our door demanding to know why we did absolutely nothing.
As for the tyrants and warlords you speak of, how did you think they became so powerful? Many of them came to power after us colonials pulled out, doing exactly what you suggest now; absolutely nothing.
In terms of power, the Cold War led to active support of tyrants by the West, to prevent communist revolution or to prevent them becoming too friendly with the Soviet Union. Idi Amin, Mubutu... the list goes on. Today those countries are picking up the pieces.
The tyrants, left to their own devices, couldn't give a damn for their people - why educate them, for instance? If they can read they might get hold of a foreign newspaper and learn the truth of their country's position in the outside world. Why give them basic health care? That new set of Mercedes-Benz limosines would be a far better choice. Or how about that new tank? Would be very useful if the people get a bit 'upperty'.
When a tyrant does fall, another replaces him. Even if the new leader had good intentions, when he sees the true state of his country, he'd much rather tred the path of the 'tyrant' he deposed rather than do anything to solve the problems of his country.
Finally, if you want to isolate Africa completely from any outside influence, you are going to have to remove all the Christian groups working there. Something in their religion might prevent that, though.