The romantic and ideological inspiration for guerrilla operations originated with Mao Tse-tung and the Chinese Communists and was refined by Che Guevara. This area offers particularly attractive conditions for guerrilla operations, including dense jungles and marshes in which troops can hide, a predominantly rural population often cut off from direct influence from the central government, undeveloped communication facilities between villages and urban centers, and long, unprotected frontiers that permit easy infiltration and supply of materiel from the "active sanctuary" (the country promoting the unconventional warfare). In Southeast Asia, however, Noth Vietnam and Communist China played major roles in organizing, training, and supporting "national liberation" movements operating in Malaya, South Vietnam, Laos, Cambodia, Thailand, and Malaysia.
Successful guerrilla campaigns in Cyprus, China, and Cuba were basically internal rebellions, conducted with a minimum of external interference. Some of the longest and most tragic unconventional military operations have been purely domestic affairs, as in Colombia, where internal strife with characteristics of guerrilla warfare has killed several hundred thousand people over the last thirty years. Of course, not all guerrilla operations have been organized, supported, or directed by an outside power.
This type of revolutionary activity, which combines terror with mobile guerrilla attacks, was used extensively in Yugoslavia and other occupied countries during World War II and has since occurred in more than fifteen countries. As the focus of the cold war shifted from Europe to Asia, Africa, and Latin America, guerrilla warfare supplanted some of the conventional techniques of subversion discussed above.