What was the world's response to Steve Biko and Nelson Mandela?
I think that a bit more detail or clarification is going to be needed to the idea of "world's response." On one hand, leaders like Mandela and Biko helped to bring about much by way of political condemnation of South African apartheid. For a large period of time, South Africa was seen as a pariah in the world community for its practice of apartheid. With that being said, I also think that the world truly lacked the full understanding of how bad things were and what specifically leaders like Biko and Mandela had to endure. There were so many other conditions in the world which received attention from the world community that it seemed like the forces of oppression that Biko and Mandela were struggling against appeared not to really merit that much in terms of authentic and meaningful world response and public reaction. Consider that if the world community heard today that students were protesting and were mowed down by government troops, such as what happened in Soweto as inspired by Biko, the world reaction might be more significant today than back then. We don't know because it's hypothetical, but I think we can assess a meaningful and lasting world response as something that was not entirely present in the past. In the end, more specific detail has to be given relating to the idea of "world's response."