The Khmer Rouge is remembered mainly for the deaths of an estimated 1.5 million people (estimates range from 850,000 to 3 million) under its regime, through execution, starvation and forced labor. Following their leader Pol Pot, the Khmer Rouge imposed an extreme form of social engineering on Cambodian society - a radical form of agrarian communism where the whole population had to work in collective farms or forced labor projects. In terms of the number of people killed as a proportion of the population (est. 7.5 million people, as of 1975), it was one of the most lethal regimes of the 20th century. One of their mottos, in reference to the New People, was: "To keep you is no benefit. To destroy you is no loss."

Vietnamese forces colluded with khmer rouge forces

The khmer rouge also murdered an estimated 200,000 ethnic chinese with the backing or tacet support of the CCP in china. Follow the US withdrawal in 1973 and the fall of Saigon in 1975 southeast asia became a killing field wars between former allies broke out including Vietnam and cambodia, and China and vietnam.