Historical Dictionary



One of the best-known French theoreticians of “revolutionary warfare, who got his start during the Indochina War. Lacheroy joined the École spéciale militaire at Saint-Cyr in 1925. In 1927, he transferred to the colonial infantry, serving in the Upper Volta in a regiment of Senegalese tirailleurs between 1928 and 1930. He subsequently moved on to Syria, where he learned of the exploits of Lawrence of Arabia and concluded that victory in guerrilla war depended on “psychology”. He was arrested in Rabat in December 1940 for assisting French resistance agents. Though the charges were unfounded, he ended up in jail in Clermont-Ferrand, sharing a cell with none other than Pierre Mendès France. Released for lack of incriminating evidence, Lacheroy returned to Vichy North Africa before joining Free French forces upon the Allied landing there in 1942. He took part in the liberation of Italy under General Alphonse Juin, and then served under General Jean de Lattre de Tassigny in the 1st French Army taking part in the liberation of France and Germany.

In February 1951, after working in the Ivory Coast, he landed in southern Vietnam where he took command of the Bien Hoa Zone. It was also there that he began studying in detail the Viet Minh’s guerrilla tactics and developing his ideas on counter-insurgency, thanks to the archives of the Deuxième Bureau in charge of southern Vietnam. In 1952, he ran an internal conference for officers in his sector on the organizational and psychological nature of the Viet Minh’s warfare, entitled Une arme du Viet Minh: les hiérarchies parallèles. He emphasized how the communists effectively organized and controlled the populations as a weapon and he popularized the idea of parallel hierarchies in French military science. Lacheroy also discovered the military writings of Mao Zedong on “revolutionary war”.

All this launched something of a new career for him as theoretician and instructor in what he (and others) would call guerre révolutionnaire. He returned to France in mid-1953 to teach such subjects at the Centre of Asian and African Studies within the Colonial Army headquarters. An excellent speaker, he propounded his ideas on counter-insurgency and psychological warfare and began to attract the interest and attention of high-ranking army strategists, theorists, and leaders facing similar wars in the Empire. Indeed, his understanding of Vietnamese communism and the adversary’s organization, adaptation, and use of guerrilla, communist and psychological strategies would serve as a model for counter-insurgency fighting during the Algerian War and elsewhere. In 1955, Lacheroy ran a pivotal conference bringing together his ideas (and those of others) on counter-insurgency, entitled Action Viet Minh et communiste en Indochine ou une leçon de “guerre révolutionnaire”. In 2003, he published his memoirs, entitled De Saint-Cyr à l’action psychologique. See also ANTOINE SAVANI; GROUPEMENT DE COMMANDOS MIXTES AÉROPORTÉS (GCMA); ROGER TRINQUIER; SERVICE ACTION.