- Cambodian Citizens (Primarily Urban Dwellers): After the Khmer Rouge take over in 1975, Cambodian urban dwellers were forcibly removed from their homes and moved to rural centers. Often, these citizens transported themselves through long marches, in which many died due to hunger, exhaustion, and disease. Other times, citizens were transported through cramped train car. Once in these rural areas, Cambodians were forced into labor camps where each individual was given a small food ration each day - barely enough to maintain physical and/or mental strength. Hunger and disease were rampant and families were forcibly separated as it violated the ideologies of the Khmer Rouge.
- The Khmer Rouge: After gaining considerable force after former Prince Sihanouk joins its ranks, the Khmer Rouge was the main political and ideological organization in power during the Cambodian Genocide. Days after its take-over of Phnom Pehn, the Khmer Rouge began an extremist program, modeled after Communist China's regime. They desired to create an agrarian utopian environment in which the entire nation worked on collectivized farms, with time beginning at Year Zero. All dissidents, intellectuals, and Buddhist monks were promptly executed because their ideologies conflicted with those of the Khmer Rouge. All political and civil rights were abolished and children were forcibly removed from family members, as the parental authority figure was now the Khmer Rouge.
- Vietnam: Vietnam plays a particularly complex role in the Cambodian Genocide as its own civil war conflicts prompted its presence in nearby Cambodia. Furthermore, its presence allowed for the United States to be present in Cambodia, as well. Later on during the genocide, while Vietnam and Cambodia begin their own war, communist Vietnam eventually takes over Cambodia, overthrowing the Khmer Rouge. While both countries were technically communist, Vietnam did not follow a Chinese model of Communism, one that differed from a Soviet model.
- The United States: The United States plays a quite infamous role in the Cambodian genocide. In trying to rid Cambodia of Viet-Cong guerilla groups, the United States military killed thousands of Cambodian citizens, primarily during air raids. Furthermore, the United States continues to provide support for the Khmer Rouge while its conflicts with Vietnam continued as the Khmer Rouge were also enemies of Vietnam. While the United States did offer humanitarian support after the genocide, it was undoubtedly complicit in many of these atrocities.