Che Guevara
In Guevara's private writings from this time (since released), he displays his growing criticism of the Soviet political economy, believing that the Soviets had "forgotten Marx". This led Guevara to denounce a range of Soviet practices including what he saw as their attempt to "air-brush the inherent violence of class struggle integral to the transition from capitalism to socialism", their "dangerous" policy of peaceful co-existence with the United States, their failure to push for a "change in consciousness" towards the idea of work, and their attempt to "liberalize" the socialist economy. Guevara wanted the complete elimination of money, interest, commodity production, the market economy, and "mercantile relationships": all conditions that the Soviets argued would only disappear when world communism was achieved. Disagreeing with this incrementalist approach, Guevara criticized the "Soviet Manual of Political Economy", correctly predicting that if USSR did not abolish the law of value (as Guevara desired), it would eventually return to capitalism.
Third World Socialism
Because of its close proximity and strong historical connection to the United States, Cuba served an integral role in spreading socialism to the rest of Latin America. Che Guevara described Cuba as "a guiding light" to Latin American countries caught in conflict between imperialism and socialism. In Guevara's speech "On Revolutionary Medicine", he recounts his travels through Latin America and the misery, hunger and disease he witnessed and explained how a shift to socialism could help alleviate these struggles. As part of the New Left, Fidel Castro and Che Guevara implemented leftist politics in Cuba while incorporating policies aimed at addressing social issues. Cuban officials intended for Cuba to spur similar leftist revolutions in the rest of Latin America, what he saw as a common "liberation struggle", in countries like Venezuela, Bolivia and Nicaragua.