<P> In Africa, Somali army officers led by Siad Barre carried out a bloodless coup in 1969, creating the socialist Somali Democratic Republic . The Soviet Union vowed to support Somalia . Four years later, the pro-American Ethiopian Emperor Haile Selassie was overthrown in a 1974 coup by the Derg, a radical group of Ethiopian army officers led by the pro-Soviet Mengistu Haile Mariam, who built up relations with the Cubans and the Soviets . When fighting between the Somalis and Ethiopians broke out in the 1977--1978 Somali - Ethiopian Ogaden War, Barre lost his Soviet support and turned to the Safari Club--a group of pro-American intelligence agencies including Iran, Egypt, and Saudi Arabia--for support and weapons . The Ethiopian military was supported by Cuban soldiers along with Soviet military advisors and armaments . </P> <P> The 1974 Portuguese Carnation Revolution against the authoritarian Estado Novo returned Portugal to a multi-party system and facilitated the independence of the Portuguese colonies Angola and East Timor . In Africa, where Angolan rebels had waged a multi-faction independence war against Portuguese rule since 1961, a two - decade civil war replaced the anti-colonial struggle as fighting erupted between the communist People's Movement for the Liberation of Angola (MPLA), backed by the Cubans and the Soviets, and the National Liberation Front of Angola (FNLA), backed by the United States, the People's Republic of China, and Mobutu's government in Zaire . The United States, the apartheid government of South Africa, and several other African governments also supported a third faction, the National Union for the Total Independence of Angola (UNITA). Without bothering to consult the Soviets in advance, the Cuban government sent a number of combat troops to fight alongside the MPLA . Foreign mercenaries and a South African armoured column were deployed to support UNITA, but the MPLA, bolstered by Cuban personnel and Soviet assistance, eventually gained the upper hand . </P> <P> During the Vietnam War, North Vietnam invaded and occupied parts of Cambodia to use as military bases, which contributed to the violence of the Cambodian Civil War between the pro-American government of Lon Nol and communist Khmer Rouge insurgents . Documents uncovered from the Soviet archives reveal that the North Vietnamese invasion of Cambodia in 1970 was launched at the request of the Khmer Rouge after negotiations with Nuon Chea . US and South Vietnamese forces responded to these actions with a bombing campaign and ground incursion, the effects of which are disputed by historians . Under the leadership of Pol Pot, the Khmer Rouge would eventually kill 1--3 million Cambodians in the killing fields, out of a 1975 population of roughly 8 million . Martin Shaw described these atrocities as "the purest genocide of the Cold War era ." Backed by the Kampuchean United Front for National Salvation, an organization of Khmer pro-Soviet Communists and Khmer Rouge defectors led by Heng Samrin, Vietnam invaded Cambodia on 22 December 1978 . The invasion succeeded in deposing Pol Pot, but the new state would struggle to gain international recognition beyond the Soviet Bloc sphere--despite the previous international outcry at Pol Pot's DK regime's gross human rights violations, and it would be bogged down in a guerrilla war led from refugee camps located in the border with Thailand . Following Khmer Rouge's destruction, Cambodia's national reconstruction would be severely hampered and Vietnam would suffer a punitive Chinese attack . </P> <P> As a result of the Sino - Soviet split, tensions along the Chinese--Soviet border reached their peak in 1969, and United States President Richard Nixon decided to use the conflict to shift the balance of power towards the West in the Cold War . The Chinese had sought improved relations with the Americans in order to gain advantage over the Soviets as well . </P>

Who was all involved in the cold war