Let's say the
unholy alliance wasn't just rhetoric but a formalized system. Let's start with an alternate
Congo Crisis where South Africa, the Central African Federation, and the Portuguese support Katanga and South Kasai to the extent that allow the breakaway provinces to gain independence, and so recognize them. The Central African Federation later becomes Rhodesia in some similar form, and ruled by the same type of people. This group, buoyed with trade with each other, Belgium, and France (now with a more demented version of
Françafrique due to the prior existence of a Pied Noir enclave based in
Oranais), goes on to aid Biafra in a successful war of independence. And then maybe get involved in other conflicts in the rest of the continent, creating other allies, proxies, and so on.
This turns Africa into an international flashpoint on par with the Middle East rather than a place of (mostly) localized conflicts. Greater Soviet meddling to support pan-Africans and local African anti-colonialists. Greater Western meddling to support some of the white neocolonial states, but also to support some black democratic movements.
How will this play out? Obviously the various white colonial regimes will fall sooner or later, but when and how?