The primary objective of the Khmer Serei was to destabilize the existing powers held by the then-Cambodian leader, King Norodom Sihanouk and to overthrow his reign – and to become a permanent part of the Cambodian body politic.
In examining the political ambitions of Son Ngoc Thanh, we will better understand the reasons for the eventual formation of the Khmer Serei and their activities.
While at the institute, he took the opportunity of his position as secretary and empowered patriotic monks to spread Buddhist and nationalistic sermons throughout Cambodia and into the Mekong Delta.
Upon his return to Cambodia, Thanh resumed his political activities and founded a newspaper whose rhetoric angered Sihanouk and his French advisers, thereby risking imprisonment.
[4] From 1952 to 1954, the Khmer Issarak carried out small-scale attacks against local police and initiated audio broadcasts of anti-Sihanouk propaganda messages along the Thai-Cambodian border.
Strategically, they operated mainly from bases on the Thai and Vietnamese borders, recruiting from the Khmer Krom minority of the Mekong Delta in Vietnam.
The Khmer Serei continued to be a source of disturbance to the Sihanouk government, organizing dissident activities along the border provinces of Cambodia.
Moving back to the Mekong Delta area gave Thanh the potential to recruit new members from the large populations of Khmer Kroms living there.
In addition, the U.S. Special Forces and its Civilian Irregular Defense Group (CIDG) would become its allies, and recruited the Khmer Serei into its ranks.
This was beneficial on two fronts: firstly, the monetary rewards from joining the CIDG were more regular and higher than what they previously obtained and therefore many were recruited; secondly, the Khmer Serei was able to maintain its identity and building itself as a single cohesive force.
[14] In addition, member of the Khmer Serei has anti-communist contacts in the Cambodian Army who were sympathetic to any plan to rid Cambodia of the North Vietnamese presence.
The information provided would have been crucial to the success of any plan for a military incursion into Cambodia, and it gives an indication of the importance of the Khmer Serei's role in Operation Cherry.
The Khmer Serei were generally viewed as a minor irritant by the media but Sihanouk was infuriated by its existence and by its clandestine radio broadcast emanating from the Thai and South Vietnamese borders, which made scurrilous attacks on him and the royal family.
There were two suggested theories about these defections: the first was that Son Ngoc Thanh had order five hundred men to defect so that the Khmer Serei could infiltrate the Cambodian forces and subvert Sihanouk's government; the second was that the defectors were actually employed by the CIA in order to reinforce Lon Nol and his forces when they made their move to depose Sihanouk.
The rationale to these defections were never explained by the CIA or Thanh; however, these defectors did support Lon Nol's government to fight against the North Vietnamese forces based in Cambodia.
They were effectively used by Lon Nol to reinforce his own forces and later used to strengthen the Cambodian Army in its battle against the North Vietnamese and Khmer Rouge.
[22] At various intervals during the 1980s, these groups composed of Khmer Rouge and various pro-Sihanouk or pro-Son Sann factions conducted sporadic military activities against President Heng Samrin's Vietnamese-sponsored People's Republic of Kampuchea (PRK).
It was also reported that a number of the remaining Khmer Serei groups has become 'little more than black marketeers or bands of extortionists' who preyed on the defenseless in the border refugee camps.
In the words of Turkoly-Joczik, "like many dissident movements in Cambodia, the Khmer Serei has become an aberration, a political anomaly that haunts the Cambodian hinterlands as a specter of lost hope and a promise unfulfilled."