The Sino-Soviet ideological dispute, the Soviet Union's repressive interventions in Czechoslovakia and other Warsaw Pact countries, the presence of the Cuban Revolution in Latin America, and the emergent global student movement inspired in the humanist socialism of the Frankfurt School and the New Left (by the time of the early opposition to the Vietnam War) were the main ideological issues that the traditional Chilean left (the Socialist Party and the Communist Party) had to deal with amid their relative political stagnation in the beginning of the 1960s.