Afrol News, reports that Cuban President Fidel Castro, has revealed details of Cuban military participation in the war against South African troops in southern Angola in 1987-88.
"About 55,000 Cuban troops aided the Angolan counter-offensive, that drove South Africans back to the Namibian border and to the negotiation table". According to Castro, that forced South Africa to negotiate, resulting in the independence of Namibia.
A very detailed account is given in the article Castro reveals role in Angola, Namibia independence