While some considered him a "racist political dynast"[1] and condemned him for his collaboration with the atrocious regime of the Democratic Kampuchea, he defended himself from adhering to the ideologies of communism and presented himself merely as a Khmer nationalist.
[7] Among Khmer Communists, however, Thiounn Mumm seems to have best understood Marxism; he coldly analyzed Cambodian society and wanted to raise the educational level of the people.In 1954 following the independence of Cambodia, Thiounn returned to Cambodia and failed to be elected as a radical democrat candidate with the Pracheachon party in the 1955 general election along with Keng Vannsak, which decided him to return to France in April 1955,[9] where he started working in 1956 as an engineer for the French national centre for Scientific research (CNRS) in the physics-mathematics section.
[11][12] In 1957, Thiounn Mom hosted Prince Norodom Sihanouk during the celebration of the 2500th anniversary of the birth of the Buddha for the inauguration of the Maison du Cambodge at the Cité Internationale in Paris.
[16] At a communist congress in Beijing in 1971, Huot Sambath, Brigadier General Hu Nim, Sarin Chhak, Chea San, Thiounn Mumm, and Hak Seang Layny were chosen at the Cambodian leaders to coordinate the "national liberation struggle".
At the Fourth Party Congress in Phnom Penh in September 1978, Pol Pot unveiled a plan for a revolutionary technical education system, sharing the stage with Mumm, who was in charge of putting an "intellectual gloss" to the program.
From September 1978, on Vom Vet's orders, Mumm became directed the then Soviet Institute in Phnom Penh, to reeducate the youth of Cambodia and train a new generation of cadres in an attempt of the Angkar to display a "human face".
[23] In late 1982, when the tripartite government was formed between the Khmer Rouge, Sihanouk and Sun Sen, Thiounn returned to France on his diplomatic visa, left the party, and was reunited with his family.
Questioned by Henri Locard, Thiounn Mumm compared the revolutionary "Khmer Rouge" project to peasant revolts of Christian Anabaptist inspiration in Europe in the 16th century.
[26] Henri Locard; however remarks how dubious this comparison was: Angkorian civilization conceived of power as a mission of service to the people and established the primacy of the general interest over that of the individual.
The happiness and well-being of the people was the end of all power!Beyond this propaganda, Thiounn Mumm may have had a true concern for the heritage of Angkor Wat, despite destructions and vandalism taking place during the Khmer Rouge regime.