One thing I've never understood about the cambodian genocide is how it managed to function for 4 years, often with genocides you can kind of see a strange kind of rationality and social function with them - The Holocaust spun a narrative of Jewish evil and used that for slave labour to benefit a ruling class of Germans, similarly in Bangladesh there was a 20 year political and ideological prelude culminating in action that once again served a ruling class. All of this meant that the outcomes of the social structures and attitudes of the time were omewhat predictable.
In Cambodia however it seems like the genocide started instantaneously despite there being a completely secretive leadership structure, and that there was simultaneously no prior planning yet a stunningly organised evacuation of civilian centres.
How did this even manage to function? From what I understand urban centres were deserted for the entirety of Khmer rule, how did the country survive without administrative function, how was a genocide carried out without administration and if there was an administration, how did they survive without beng labelled as intellectuals for murder?
It seems that all the structure and order of the country was completely gone, yet it was increidbly organised, could someone please shed some light on how it all worked?
You might like to read some of these answers to get a better idea of what actually happened in Cambodia from 1975-1979.
What were the reasons for KR intellectual killings?
Was what happened in Cambodia a unique form of Genocide?
What happened to Phnom Penh and other cities after the evacuations?
Why did the KR force the population out of the cities?
A couple of points from your question I want to address here as well however. It is a common misconception that the state of Democratic Kampuchea was simply a kind of anarchic, agrarian, bloodbath. This really wasn't the case, there was administration. It was a centrally powerful government, that stayed in Phnom Penh (which maintained a population of about 50,000 who kept the city working to some degree etc). Another misconception is about how the killings were undertaken, there was no central directive from the CPK to 'kill all the intellectuals' or something of that nature, there was no 'genocide' in the traditional sense. The two million or so Cambodians that died came from a variety of backgrounds, and died for different reasons relating to the aims of the CPK. It is more appropriate to consider the mass death that occurred in similar terms as the Great Leap Forward or the War Communism of the early Soviet Union.
In regards to this notion that anyone who was educated was considered to be a counter-revolutionary, this was not the case either. Many Khmer Rouge were teachers in the 50's and 60's, and many members of the central committee were students in Paris, Khieu Samphan for instance had a Phd.
Concepts such as 'year zero' (which was a phrase coined by those looking at the events abroad not by the Khmer Rouge themselves) gives the impression that the whole project was an attempt to return Cambodia to some ancient past and kill everyone who ever saw a car or a television set. This really wasn't the case, it was a socialist revolution taking cues from the Soviets, Vietnam and Mao. They simply attempted to go as fast as possible and as 'pure' as possible, and found it expedient to kill those suspected of undermining that aim rather than 're-educating' them.
I wrote this in a bit of a rush, if you have any more questions feel free to ask.