In 1978 the Khmer Rouge took power in Cambodia. The regime was brutal, many citizens died or left. The leader was a vicious and repugnant fat man who terrorised the population and even to this day many still recoil in horror at the memory of his short but horrific time in charge. Then the cavalry arrived in the shape of the Vietnamese, they got rid of the repugnant fat man (now dead) and took over the country. The Vietnamese still control Cambodia although it is with a very light touch. Some Cambodians would like a stronger presence but most are pretty happy with the way things are done now. There are other places they can go if they don't like the way Cambodia is run. They can go to Burma or Laos where the control and rules are very strict and very strongly enforced by a small hierarchy. The huge majority of Cambodians remember the repugnant fat man and although occasionally the Vietnamese annoy them they remember what the Vietnamese did and continue to do and that without them they would probably be gone.