South Africa's COIN war in SWA/Namibia/Angola

[JMA]

It would be interesting to learn how they believed to be able to supply the brigade behind the OPFOR better than OPFOR would be able to supply its spearhead?
This is the classic problem of encirclements.

Yes, and also a question of time.

South Africa was restricted to reasonably quick in-and-out forays into Angola where battle-groups or brigades were used (while smaller stuff was in there all of the time). It was necessary to get in, do the business and be out or on the way out by the time an international political row blew up.

There was no way that a South African force would be allowed (by the politicians) to sit astride the Angolan/Cuban supply route for any length of time as it would then be portrayed as an occupation rather than a raid.