They smashed babies against trees and murdered nearly 2 million Cambodians in under 4 years chasing a pure agrarian communist utopia with no cities, no money, and no private property. On April 17 1975, the Khmer Rouge rolled into Phnom Penh and within hours emptied the entire city, marching hospital patients and the elderly into the countryside on foot as they declared Year Zero and set out to erase every trace of the old society. Anyone tied to the past became a target and wearing glasses alone could get you killed because it proved you could read, while doctors, teachers, engineers, and monks were executed as enemies of the revolution. They turned a high school into a prison where roughly 20,000 people were tortured into confessing crimes that never happened, after which they were trucked to mass graves in the killing fields where executioners smashed infants against the killing tree to save bullets. But they never achieved a classless utopia so it wasn’t like real communism.