South Africa, accounting on its own for more than one-third of Africa's GDP, is still the key country in all this. And here, despite opinion polls showing 70 per cent support for him, Obama faces a hard sell. ANC leaders used to like to socialise with New York's ex-mayor David Dinkins - it helped that Dinkins had been defeated by "white racism" - but Dinkins was utterly shaken when a live goat was sacrificed in his honour, and didn't return.

Nelson Mandela became a close friend of President Clinton - helping him through his Monica moment - and was generally allowed such latitude that when he publicly told Clinton that if he tried to dissuade him from his friendship with Gaddafi, he could go "jump in the lake", Clinton just roared with laughter. Then, in early 2001, President Thabo Mbeki had to confront the world's most powerful black politician, the US Secretary of State, Colin Powell. Mbeki, whose aspirations to grandiosity were almost unlimited, clearly saw Powell as a rival and, as a black Republican, also a sell-out.

The first great confrontation came with the UN World Conference Against Racism, in Durban in September 2001. Mbeki had announced that the next decade would be dedicated to the struggle against racism and it was clear that the conference was supposed to magnify this on the world stage, replete with reparations for slavery and other colonial crimes. An NGO forum preceded the conference proper, adopted strongly anti-Israel positions and refused to balance this by condemning the evils of anti-Semitism. Israel walked out, swiftly followed by the US - which ruined the conference. The whole idea had been that the most powerful white nation, America, must be there in order to be condemned, to be allowed to apologise - and become the biggest reparations donor. Colin Powell, back in Washington, had pulled the plug on all of this.

He clearly blamed South Africa for the denouement: it was the host, it had encouraged an anti-Israel and anti-US atmosphere and it had by far the largest number of delegates and activists at the conference. Mbeki's response was furious and immediate: suddenly it was announced that it would not, after all, be possible for the flagship of the US fleet, the USS Enterprise, to dock in Cape Town as planned, much to the chagrin of local shopkeepers who had been happily anticipating 6,000 free-spending US sailors. Then, just three days after the WCAR closed, the cataclysm of 9/11 occurred. Mbeki termed the event a "terrible tragedy" and Mandela roundly denounced the terrorists. But almost immediately Pretoria began to sound a note strongly critical of the US/UK strikes into Afghanistan and, as Muslim opinion hardened, so did that of the South African government. More than 1,000 South African Muslims were allowed to fly out to fight for the Taliban.