Was the apartheid government in SA the most stable government of the 20th century in Africa?

My answer on  Quora

It all depends on how one defines stability. The National Party was in power in South Africa between 1948 to 1994 (which I believe is an African 20th century record). In terms of single party control this indeed was rather extensive. However apartheid was inherently an unstable system as seen by the Sharpeville massacre, the Rivonia trial, the Biko affair, the Soweto riots and the mass protests in the 1980s. The system was sustained by a strong police and military presence that created an illusion of stability. At the core it was rotting away.

Once the political structure was undercut by economic sanctions, political isolation and a further demographic power imbalance it was only a matter of time before it would collapse.

On an ideological level (and I say this as a South African) the Apartheid government made group identity the mantra of its policy. When this comes at the expense of the rights of the individual then one has the trappings for the genesis of a volatile outcome.