Both Nelson and Winnie, at different times, have to deal with the limits of "non-violence", and Winnie, especially, rails about the need to discipline her troopers. Sacrifice is always on the table.
I recall that the 1950 World Book Encyclopedia (which my parents bought) treats the "Union of South Africa" as a reputable country, as its article was developed just two years after the 1948 laws were passed.
Checkout Richard Attenborough's 1987 film "Cry Freedom". Also, "Invictus" is reviewed here Dec. 14, 2009.