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.
Ñancahuazú Guerrilla
At a meeting in Madrid, Juan Perón, who was sympathetic to Guevara but disapproved of Guevara's choice of guerrilla warfare as antiquated, warned Guevara about starting operations in Bolivia.
Che Guevara entered Bolivia with the pseudonym "Adolfo Mena González" on November 3, 1966. Three days later, he left the capital city of La Paz for the countryside. He planned to organize a foco with Bolivia as his target. Planning to start a guerrilla campaign against the military government of President René Barrientos, he assembled a band of 29 Bolivians, 25 Cubans, and a few foreigners which included Guevara himself, one woman from East Germany named Tamara Bunke, and three Peruvians. This small but well-armed group carried out two successful ambushes against two army patrols in the spring of 1967, but failed to gain significant support from fellow opposition groups in Bolivia's cities or from local civilians, some of whom willingly informed the authorities of the guerrilla's movements. By mid 1967, Guevara's men soon became fugitives, hunted down by Bolivian special forces and their American advisers. In the last few months of the venture, Guevara wrote in his diary that: "Talking to these peasants is like talking to statues. They do not give us any help. Worse still, many of them are turning into informants." On August 31, 1967, a small group of Guevara's soldiers, totaling eight men as well as Tamara Bunke, were ambushed and killed by Bolivian soldiers while they were attempting to cross the Rio Grande in Bolivia. On October 8, 1967, most of Guevara's surviving soldiers were surrounded and destroyed as a fighting force. Still, some were still active across Bolivia during the rest of October and November 1967. Barrientos was very concerned with Guevara's rising insurgency there, and clamped down in the area with some very heavy-handed measures (such as the Massacre of San Juan). Guevara felt that such an atrocity by the Bolivian Army and Air Force would be the tipping point in his favour in rallying the miners to his Communist cause, but eventually the miners signed with government-owned mining company, COMIBOL, an agreement which Guevara felt undermined his reason for being there.