I don't think it's ASB at all. But it requires a POD right after WWII.
After the UN is formed in 1945, they create a program to promote greater development of colonies of the former powers, with the goal of introducing prosperity to as much of the world as possible. Since India became independent in 1947 and most colonies were long gone in most other places by then, the majority of this money went to Africa. The 1950s and 1960s see massive development programs, largely funded by the USA as part of the Marshall Plan and its successors and also by the colonial powers. Britain, France, Portugal and others benefit from this as well. The Red influence that caused so much problems in Africa as a result is curtailed.
Problems still exist in many places of Africa, particularly in the Congo and Rhodesia. Congo's 1960 independence still rapidly sinks into civil war, but this time the world, led by Britain, gets involved. The Belgians let the troublesome colony go, and things have settled into stability by the late '60s.
Rhodesia is more troublesome. More than half a million whites live in Rhodesia by 1960, and the "Winds of Change" speech by MacMillan causes more problems, as apartheid South Africa stokes the problems in Rhodesia. Progressives like Garfield Todd shoot the gap between the Rhodesian whites and others, helped by socialist leaders like Kenneth Kaunda and Herbert Chitepo lead. Rhodesia declares independence on its own in 1964, and the white-led government of Ian Smith immediately consolidates white rule. But with Britain in the Congo, Smith's government is immediately in trouble.
In 1965, US President Lyndon Johnson, seeing the increasing problems of communism both in Vietnam and Africa, starts funneling aid to African nations. Better governed ones like Botswana and Tanzania get the aid first.
Rhodesia's white government by 1970 is under political pressure. South Africa's help is only able to help so much. By this time, Mugabe has declared war on Smith's government, but Chitepo, Nkomo and Kaunda kept the protests peaceful. The loss of cheap black labor ended the possibility of Smith's government surviving, and he backed down and accepted all-race elections in 1972. Kaunda handily won, but the Rhodesian constitution limited a Prime Minister to ten years in power, and Kaunda respected the rule, leaving power in 1982.
In 1975, Africa's leaders, led by Kaunda, Joseph Kasa-Vubu, Julius Nyerere, Jomo Kenyatta and Egypt's Anwar Sadat, who was trying to distance himself from the often extreme Arab states, set up the African Union, an organization designed to help the continent itself. It's first objective was destroying apartheid, but that plan got sidetracked quickly.
Angola and Mozambique became independent in 1975, which almost immediately sent mineral-rich Angola into civil warfare. The repeated failures of Soviet and Chinese attempts to take over or influence the new countries in the 1950s and 1960s leads to a determined attempt to consolidate power in the hands of the MPLA. The USA however, having seen Britain and its European allies succeed in the Congo, was not willing to let the Russians win in Angola.
The American war in Angola became infamous for its length, but most military experts and historians say the US military's crumbling after Vietnam was stopped dead in Angola. The US first landed troops in 1976, and the last US soldiers did not leave until 1988. But during that time, the US' view in Africa was changed forever.
The MPLA and UNITA fought numerous times, but when the US showed up the communist nations stepped up the offensive and sent tons of equipment to the conflict, helped quite openly by South Africa, seeing the war as a possibility to help save the fading apartheid state. The US, whose forces never numbered more than 135,000, came with the latest firepower. Better still, almost 60,000 engineers followed them. Angola came out of the war with an almost first-world infrastructure, virtually all of it built with US money.
The other African nations focused their attention on South Africa. But the US armed and built infrastructure for much of these nations too. From Zambia's incredible new University of Zambia campus in Lusaka to more than 60,000 miles of roads and 5,000 primary schools, the US forces found themselves making life much easier for the civilians.
South Africa intervened directly in 1980, but their attempts found themselves shooting at US Marines and their Mirage jets found themselves being smoked by American F-14 Tomcats. After five months the SADF withdrew, bloodied badly.
The MPLA's popular support lost ground rather rapidly over time. Savimbi rode victorious into Lusaka in May 1978, but the insurgency in Angola lasted well into the 1990s. As with ZANLA in Rhodesia, the MPLA just would not give up no matter how long the odds.
The US by the 1980s under Jimmy Carter (1977-1981), Ronald Reagan (1981-1985) and Henry M. Jackson (1985-1991) provided lavish aid to Africa, and only demanded that Washington's requests be listened to. The African leaders were only too happy to do this, having not forgot who built their nations.
With several prospering African nations on their borders, South Africa's infamous apartheid crumbled. Jackson in particular devoutly supported the idea that if the US built the infrastructure and trained the people, that the good deeds would not be forgotten and that would work better than constant aid. He turned out to be more right than he ever imagined. Carter's disgust towards apartheid was not quite matched by Reagan and Jackson, but all of them universally derided.
By 1990, apartheid was still alive - barely. But Botswana, Rhodesia and Mozambique were prospering, and sub-Sarahan African was a place that started to attract serious investment and massive numbers of tourists. A measure of the prosperity was a 1991 study of the best places to live in the world ranked Rhodesia 28th and six African nations made the top 40.
1991 saw Scoop Jackson die from an Aortic Aineurysm in office at 79, and his funeral was attended by 46 African leaders, and just about every leader of the free world. USSR Premier Gorbachev too came to pay his respects. His vice-president, Bill Clinton, continued his legacy. Clinton was elected in his own right in November 1992.
In 1991, Apartheid finally crashed hard. ANC Youth League boss Chris Hani, who had spent years on the run, was arrested by police outside Johannesburg, and died two weeks later, tortured to death by South African police. South Africa promptly blew up, and the SADF was soon forced to fight for its own nation, and divide and conquer violence amongst tribes erupted simultaneously. By mid-1992, South Africa was a mess. The ANC led by Jacob Zuma had engaged in massive violence in the highveld, and the white regime had consolidated its control over the Cape Province and was returning the favor.
Clinton rammed the white government into talking with the moderate ANC, led by Nelson Mandela and Steve Biko, who returned from Rhodesia to be part of the negotiations. The white government was cornered, but the clincher was put forward by Europe. In a repeat of Europe's 1960s intervention in Congo, the newly-formed European Union offered to put a force between the Republic-controlled area and the US offered to not only provide security but provide money to fix the country. African nations backed this up in no uncertain terms, offering everything from dirt cheap oil (Angola) and coal (Rhodesia) supplies to exclusive access to industrial minerals. But all of the nations demanded the end of apartheid, and all of the nations demanded the reunification of the country.
President FW de Klerk relented and quickly dismantled apartheid laws. South African whites, remembering having abandon half the country, saw the chance to save the other half and jumped at it. Zuma on the other hand would not accept it at all, and demanded the total destruction of the Republican government now in Cape Town.
The US and the EU chose the side of South Africa, particularly after the November 1993 elections, in which the National Party after 45 years handed the government to the ANC, led by Mandela. The remaining Republic of South Africa was a very racially mixed state - 6.7 million whites, 2.5 million coloreds, 875,000 Indians and 8.9 million black Africans.
Zuma formally established his republic of Azania in November 1992, but the collapsing Soviet Union wasn't able to provide much in the way of support, but the Chinese government provided enough that Zuma stayed afloat, despite his neighbors hating his guts.
By 2008, South Africa is the wealthiest country on the continent, an associate of the European Union and has a per capita income on par with countries such as Argentina and eastern Europe. Mineral-rich Rhodesia and Botswana and oil-rich Angola are not far behind. The Congo is the breadbasket of Africa and much of the west. The port at Matadi, Congo, is the world's busiest commodities port. It became possible for the first time in 1992 to drive from Cairo to Cape Town, and train travel between the two distant African nation became possible in 1997.
Literacy rates on the continent range from 98% in South Africa to just below 50% in much of West Africa. Life expectancy ranges from 47 years (Azania) to 81 years (South Africa). AIDS is a scourge in Africa, but it is only out of control in certain parts of it.
Dictatorships exist in a few nations - Azania, Malawi, Zanzibar, Somalia, Sudan - but democracy is the rule rather than the exception in Africa.