The foco theory of revolution by way of guerrilla warfare, also known as focalism (Spanish: foquismo), was inspired by Marxist revolutionary Ernesto "Che" Guevara, based upon his experiences surrounding the rebel army's victory in the 1959 Cuban Revolution, and formalized as such by Régis Debray. Its central principle is that vanguardism by cadres of small, fast-moving paramilitary groups can provide a focus (in Spanish, foco) for popular discontent against a sitting regime, and thereby lead a general insurrection. Although the original approach was to mobilize and launch attacks from rural areas, many foco ideas were adapted into urban guerrilla warfare movements by the late 1960s.
Foquismo, which was theorized by Régis Debray, draws on Ernesto Guevara's experience of the Cuban Revolution, where a small group of 82 members landed in Cuba on board of the Granma, in December 1956, and initiated a guerrilla war in the Sierra Maestra. During two years, the poorly armed escopeteros, at times less than 200 men, managed to win victories against Batista 's army and police force, which numbered between 30,000 and 40,000 in strength The small group finally managed to take La Havana after the December 1959Battle of Yaguajay. This surprising success led to the foquismo theory which, inspired by Mao's doctrine of People's war, counted on the support of the people to win the war. But the foquismo theory stated that this popular support would be created during the armed struggle itself: thus, against predominant Marxism theory, there was no need to wait for the "objective conditions" of a popular uprising to engage the last stage of the revolutionary struggle (i.e. armed struggle). In other words, a small group of revolutionaries was considered to be enough to jumpstart a revolution since this group could begin the revolutionary struggle while at the same time developing the conditions necessary for popular support for the revolution. This theory focused heavily on the notion of vanguardism and on the moral value of the example.
