A mere hour's drive separates the prison farm where Nelson Mandela is being held and State President P.W. Botha's white-pillared residence in Cape Town. But the political distance between those two men has always seemed unbridgeable. They have personified the country's racial stalemate: Mandela, who turns 71 this week, insisted that he would make no deals with the white government while he remained a prisoner; Botha, 73, vowed that he would never free the symbolic leader of the nation's black majority unless Mandela forswore the use of violence.
To the astonishment of black and white South Africans, the government disclosed last...