A guerrilla foco is a small cadre of revolutionaries operating in a nation's countryside. This guerrilla organization was popularized by Che Guevara in his book Guerrilla Warfare, which was based on h
Raúl Castro (left) and Che Guevara (right) in their Sierra de Cristal Mountain stronghold south of Havana, in 1958. It was during this time as a guerrilla commander in the Cuban Revolution, that Guevara would base his theory of a foco-centered revolution.