The Cuban intervention in Angola (codenamed Operation Carlota) began on 5 November 1975, when Cuba sent combat troops in support of the communist-aligned People's Movement for the Liberation of Angola (MPLA) against the pro-western National Union for the Total Independence of Angola (UNITA) and National Liberation Front of Angola (FNLA). The intervention came after the outbreak of the Angolan Civil War, which occurred after the former Portuguese colony was granted independence after the Angolan War of Independence. The civil war quickly became a proxy war between the Eastern Bloc led by the Soviet Union and the Western Bloc led by the United States. South Africa and the United States backed UNITA and the FNLA, while communist nations backed the MPLA.
Some 4,000 Cuban troops helped to turn back a three-pronged advance by the SADF, UNITA, FLNA, and Zairean troops. Later, 18,000 Cuban troops proved instrumental in defeating FNLA forces in the north and UNITA in the south. The Cuban army also assisted the MPLA in repressing separatists from the Front for the Liberation of the Enclave of Cabinda (FLEC). By 1976, the Cuban military presence in Angola had grown to nearly 36,000 troops. By effectively driving out the internationally isolated South African forces, Cuba was able to secure control over all the provincial capitals in Angola. Following the withdrawal of Zaire and South Africa, Cuban forces remained in Angola to support the MPLA government against UNITA in the continuing civil war. South Africa spent the following decade launching bombing and strafing raids from its bases in South West Africa into southern Angola, while UNITA engaged in ambushes, hit-and-run attacks, and harassment of Cuban units.
In 1988, Cuban troops (increased to about 55,000) intervened again to avert military disaster in a Soviet-led People's Armed Forces for the Liberation of Angola (FAPLA) offensive against UNITA, which was still supported by South Africa, leading to the Battle of Cuito Cuanavale and the opening of a second front.