It was fought against an unpopular dictator, who, as the battle raged, became ever more brutal and therefore ever more despised. In both the cities and the countryside, the rebels enjoyed widespread support that increased as the war continued. Indeed, by the time Guevara began his march up-country, arms, men, and money were pouring into the rebel command from inside and outside Cuba. Although he faced thousands of soldiers and police in his march, they by then had become highly demoralized.
Furthermore, although the mountain rebels often scorned and suspected their colleagues in the far-off cities, the urban allies not only harassed Batista's forces themselves, providing important diversions, but also formed a crucial part of the chain that kept the mountain guerrillas supplied. Meanwhile, the communists stood aloof until victory was in sight, constantly urging caution and believing the conditions not right for successful revolution. They had counseled prudence even before the rebel force sailed from Mexico, and therein lay a continuing irritant in the relationship between Castro and orthodox communists around the world. The duty of revolutionaries was to make revolution, said the Cubans, not to stand and wait. The communists' calls for careful preparation before attempting armed action seemed to the Cubans to be little more than a mask for timidity. On the other hand, the communists, especially the Kremlin, considered the Cubans impetuous and naive. They thought that Castro and his aides constantly failed to understand the degree of groundwork successful revolution requires and were consequently a danger to the cause—loose cannons, in short. The defeat of Batista seemed clearly to validate the Cuban position. The experience that awaited Guevara in Bolivia, however, would give the Kremlin the last word.
The Cuban rebels had another serious disagreement with orthodox communists both in Cuba and abroad. It became dogma among the mountain rebels that the guerrilla army should lead the revolution both during the war and after the victory. Here, they directly contradicted communist theory that held that the army was the tool of the party, not its boss. Castro forced the communists at home to relent on this issue, but neither he nor Guevara could force the major communist party in Bolivia to do so, thus creating a grave impediment to Guevara's insurgency there.
With the victory won in Cuba, Guevara wrote a guerrilla manual, La guerra de guerrillas, published in July 1960 with an English version, Guerrilla Warfare, appearing the following year. A discussion of guerrilla tactics and objectives, the book clearly reflected the views and methods of the Sierra Maestra leadership, putting its thoughts about revolution into a theoretical package. It quickly became prominent in a burgeoning contemporary literature on the subject of guerrilla war that included works by Mao Tse-Tung and Vo Nguyen Giap plus scores of volumes on the techniques of counterinsurgency. Unfortunately, Guevara's generalizations later proved ruinous in Bolivia.
One element remained constant, however, in every insurgency in which Guevara partook: The United States supplied and trained his enemies. In Guatemala, it created the force that overthrew the Arbenz government, which Guevara greatly admired. In the case of Cuba, it impeded funds and seized arms headed from the United States to Castro. At the same time, it provided the Cuban government with military training and supplies, even including tanks, until the collapse of Batista's regime; even though it declared an end to military aid in March 1958, supplies continued to flow through alternate channels. Batista's air force, for example, fueled and armed its aircraft at the U.S. naval base at Guantanamo in Cuba until June 1958 when Castro's brother Raul kidnapped a busload of base personnel plus U.S. and Canadian employees of nearby U.S. businesses. With some 48 hostages, he negotiated an end to the Guantanamo supply operation plus the continuing delivery to Batista of T-28 aircraft, training planes that could be armed.
In the Congo, not only did the United States supply the government forces fighting against the insurgents, but also Cuban exiles contracted by the CIA fought on the government side. Finally, in Bolivia the United States provided arms, training, and intelligence services to the Bolivian government. Guevara had very good reason to believe that in every insurgency in which he was involved, the real enemy behind the screen was the United States, hidden but visible, like a character in an Asian shadow play.