Viriato, what do you think about the possible affects on race relations in southern Africa? As far as I understand, what bothered the Rhodesians and made them wary of majority rule was the violent reprisals on Europeans in the Congo. If a Congolese leader, even a break-away one, could assure them that black leaders could rule a multi-ethnic country responsibly, do you think they'd be less likely to go the path they did. I'm hoping it would lead to a long-term Zimbabwe-Rhodesia, but that may be wishful thinking.
Many Europeans fled the Congo as refugees via Rhodesia. This frightened many whites in not only Rhodesia, but in the Portuguese colonies along with South Africa into believing that majority rule was untenable. In Rhodesia there had been at least in the 1950s a portion of the white population that felt that majority rule could be achieved peacefully. The horror stories brought by the refugees, hardened the attitude of many whites into not accepting majority rule. In Angola before 1961 there had been a group of whites that were in favour of independence, but there too many settlers began to believe it would be unworkable.
Leading up to 1965, further reprisals by newly independent African governments against European minorities hardened settler attitudes. For instance in 1962 when the independent government of Algeria reneged on the Évian accords, that had would have allowed Europeans to remain in the country, respecting their property. Then came indiscriminate killing of European settlers in northern Angola by Congolese-backed rebels of UPA in 1961.
A peaceful pro-Western state may have alleviated many of the white Rhodesian's fears, however Southern Rhodesia and Katanga were two very different territories. Katanga resembled Northern Rhodesia in that both had large European settler populations, however few of these were large landowners. Most lived in cities and towns working in mining, railways, etc. In Southern Rhodesia, over half of the land was in the hands of Europeans commercial farmers.
Kenya had some resemblance to Southern Rhodesia, but there the whites were only 1% of the population in 1960, whereas in Southern Rhodesia they were 7% of the total (dropping to 5% by 1970). In Kenya land reform was largely funded with the assistance of the British Government. Even in Kenya, by the late 1960s the European and larger Asian (Indians were around 3% of the poulation) minorities were threatened with expulsion if they did not acquire Kenyan citizenship and give up their British passports.
Finally, the expulsion of the 80,000 or so Asians from Uganda in 1972 by Idi Amin further hardened the attitudes against majority-rule in Southern Africa. The civil wars in Angola and Mozambique where the large white settler communities departed in a matter of months further added to this sentiment (some 20,000 whites from Mozambique settled in Rhodesia in 1975-1976).
Perhaps had the cold war not existed a peaceful solution could have been achieved. Namibia and South Africa both achieved majority rule after the end of the cold war and in both countries the minority interests have been largely secured. For better or worse, European and Asian minorities in most of the African countries composed the majority of skilled individuals and business owners, and expelling them would have led to economic suicide had Soviet advisers and aid not filled the gap. By the same token, western aid propped up many corrupt regimes that also would have not lasted as long as they did.