When Africans talk about Slavery today and suggest that there should be at least a token restitution for the wrongs committed , the response from the Western Governments and from ordinary Westerners is that, yes, Slavery was bad, but really it was long ago so stop going on about it so much and get on with your lives. The message is: you are such losers for going on about something that happened so long ago and you are really just trying to frind excuses for being so stupid and lazy.
This is a shameful rhetorical trick, but Westerners get away with it because Africans do not, in the larger scheme of things, have the political or economic power to force people to confront the absolute disgusting horror of slavery which helped to build up the economies of Western societies, while at the same time helping to devastate Africa.
And of course, unlike the Germans who spectacularly lost the Second World War, the collective West who supported and benefited from Slavery never lost a War. On the contrary, Western culture (such as it might be) an society are truimphant in the world today. Winners never have to apologise except in the most perfunctory way, and can bully the decendants of those they terrorised and murdered into submission and silence.
The Holocaust is (rightly) burnt into our collective conscience because the families and friends of those who were murdered by the Germans had the power and influence to ensure that the losers are demonised in a way fitting their crime. But those with the power to do the same for Slavery are the very descendants who grew rich and complacent on the rivers of blood spilt during Slavery. (I have been listening to a lot of French, so I am into rhetorical overdrive at the moment.)
I do not want to sound like President Mbeki (who has finally and irrevocably lost my vote by firing the Deputy Minister of Health for showing she cared), but inherent racism also make it difficult for even the most bleeding heart liberals to sympathise with the issue of Slavery. While movies about the Holocaust can still become popular (The Piano, Shindlers List), I cannnot imagine a movie that shows the true story of Slavery from the point of view of the Slaves (and not from the point of view of those "noble" whites who wished to free them) would ever win an Oscar and become a Box Office Hit.
The problem is, of course, that like the Israeli government, African states and their leaders may well use and abuse the history of Slavery for own effect. But this does not absolve the West from collective responsibility for the most shameful of acts done in the name of "Western Civilization".