Cuban intervention in Angola the requested financial assistance (100,000US$) it received from Yugoslavia. Portugal's sudden retreat from Angola and Mozambique in 1975 ended a history of South African military and intelligence cooperation with Portugal against the Angolan and Namibian independence movements dating back to the 1960s, later formalized in a secret alliance codenamed Alcora Exercise. It also ended economic cooperation with regard to the Cunene hydro-project at the Angolan-Namibian border, which South Africa had financed. South African involvement in Angola, subsumed under what it called the South African Border War, started in 1966 when the conflict with the Namibian independence movement, South West Africa
Angola–Soviet Union relations United States, the People's Republic of China and the Mobutu government in Zaïre. The United States, South Africa, and several other African nations also supported Jonas Savimbi's National Union for the Total Independence of Angola (UNITA), whose ethnic and regional base lies in the Ovimbundu heartland of central Angola. The government of the Soviet Union, well aware of South African activity in southern Angola, flew Cuban soldiers into Luanda one week before November 11, 1975, the date on which Angolan nationalists had agreed to declare independence. While Cuban officers led the mission and provided the bulk of the troop force,