The relationship between the Soviet Union KGB and the Cuban DGI is complex and marked by times of extremely close cooperation and times of extreme competition. The Soviet Union saw the new revolutionary government in Cuba as excellent proxy agent in areas of the world where Soviet involvement was not popular on a local level. Nikolai Leninov, the KGB Chief in Mexico City, was one of the first Soviet officials to recognize Castro's potential as a revolutionary and urged the Soviet Union to strengthen ties with the new Cuban leader. Moscow saw Cuba as having far more appeal with new revolutionary movements, western intellectuals, and members of the New Left with Cuba's perceived David and Goliath Struggle against American Imperialism.
Guevara played a key role in bringing to Cuba the Soviet nuclear-armed ballistic missiles that precipitated the Cuban Missile Crisis in October 1962. During an interview with the British newspaper Daily Worker some weeks later, he stated that, if the missiles had been under Cuban control, they would have fired them against major U.S. cities.
He also visited Pyongyang and told the press that North Korea was a model to which revolutionary Cuba should aspire.
He strongly supported Communist North Vietnam and the Viet Cong in the Vietnam War, and urged the peoples of other developing countries to take up arms and create "many Vietnams".
Guevara and Castro had agreed that the former would personally lead Cuba's first military action in Sub-Saharan Africa.
The Cuban operation was to be carried out in support of the pro-Patrice Lumumba Marxist Simba movement in the Congo-Kinshasa (formerly Belgian Congo, later Zaire and currently the Democratic Republic of the Congo).
Subsequent analysts have also shed light on aspects of cruelty in Guevara’s methods, and analysed what Fidel Castro described as Guevara’s “excessively aggressive quality”. Studies addressing problematic characteristics of Guevara's life have cited his principal role in setting up Cuba's first post-revolutionary labor camps, his unsympathetic treatment of captured fighters during various guerrilla campaigns, and his frequent humiliations of those deemed his intellectual inferiors.
Though much opposition to Guevara's methods has come from the political right, critical evaluation has also come from groups such as anarchists and civil libertarians, some of whom consider Guevara an authoritarian, anti-working-class Stalinist, whose legacy was the creation of a more bureaucratic, authoritarian regime. Detractors have also theorized that in much of Latin America, Che-inspired revolutions had the practical result of reinforcing brutal militarism for many years.
The Butcher of la Cabaña", a reference to Guevara’s post-revolutionary role as “supreme prosecutor” at the Cabaña fortress.
He looks like a rock star, but he executed a lot of people without trial or defense." Garcia’s 2005 film The Lost City, which was reportedly banned in several Latin American countries, portrayed the ruthless brutality at the heart of the Cuban revolution. Actor Jsu Garcia as Guevara is shown casually shooting wounded Batista foot soldiers where they lie.
In the United States, a country often the focus of Guevara inspired protests in the hemisphere, his image was removed from a CD carrying case after significant public opposition which compared Guevara to Osama bin Laden and Adolf Hitler.
Retail group Target Corporation issued a public apology for producing the item. American, Latin American and European writers, Jon Lee Anderson, Régis Debray, Jorge Castañeda and others contributed to demystify the image of Guevara via articles and biographies, which detailed his life and legacy in more unidealistic terms; and, in the case of Octavio Paz, was accompanied by a critical indictment of the Marxism espoused by many in the Latin American left. Political writer Paul Berman went further, asserting that the
"modern-day cult of Che" obscures the work of dissidents and what he believes is a "tremendous social struggle" currently taking place in Cuba.