If Pol Pot has a momentary break of sanity and stops tangling with the Vietnamese over the disputed islands, how long can the Khmer Rouge government last without external invasion? In four years they managed to kill 20% of the population, if they continue to suffer that rate of attrition something has to give sooner or later, but it was an external invasion that destroyed them not an internal one even after so many people died. So any ideas on what their system would be like and how long they could sustain themselves?