This article from the New York Times talks about how virtually all Khmer Rouge leaders have not been convicted for the crimes they committed during their reign.
Two things disturb me. The first is the political situation. As the article notes, "leaders of the two opposition groups, both currently in Paris, apparently believe that allowing the Khmer Rouge trials to take place under Mr. Hun Sen would bolster his image as Cambodia's strong man both domestically and internationally." While I could easily see a war crimes tribunal becoming politicized here in America, I expect better of Cambodia, especially since one-fifth of their population was killed (something which, frankly, I cannot imagine, especially as the genocide killed higher percentages of the well-educated). One must assume that the current prime minister, Hun Sen, himself a Khmer Rouge defectee, has played a role in stopping the tribunals from occuring.
But even if the Cambodian government is not responsible (or willing) enough to hold tribunals, I would have expected the Cambodian people to have committed deadly reprisals against the Khmer Rouge. However, this seems not to have happened, as even Pol Pot, the leader of the Khmer Rouge, died of natural causes.
One must wonder whether the Khmer Rouge have less of a horror factor (as compared to say, Hitler) attached to them because the numbers (1.6 or 1.7 million) are less than other genocides. I think this is partially true, but that there is no concerted effort to expose Americans to what happened in Cambodia.
I found Yale's Cambodian Genocide Project website to be very informative; it even includes pictures of political prisoners. This BBC News article from the time of Pol Pot's death was just plain scary:
While we slept in a government guest house, armed soldiers of the regime burst in on us, threatening me and murdering Professor Caldwell in his bedroom.