 The Sino–Soviet split gave North Korea and North Vietnam more independence from both and facilitated the Soviet–Albanian split.The Cuban Missile Crisis preserved the Cuban Revolution from rollback by the United States, but Fidel Castro became increasingly independent of Soviet influence afterwards, most notably during the 1975 Cuban intervention in Angola.That year, the communist victory in former French Indochina following the end of the Vietnam War gave the Eastern Bloc renewed confidence after it had been frayed by Soviet leader Leonid Brezhnev's 1968 invasion of Czechoslovakia to suppress the Prague Spring.