Published: March 27, 1988 To the Editor: Rod Nordland's a**ertion in his review of Haing Ngor's book ''Haing Ngor: A Cambodian Odyssey'' (Feb. 21) that the Khmer Rouge ''tried to exterminate or at least deliberately work to d**h a majority of the population'' of Cambodia resuscitates an especially foolish propaganda claim of the 1970's that has been rejected by every serious student of the subject. It also fails to explain why, if the Khmer Rouge aim was ''autogenocide,'' it was unable to come anywhere near meeting its objective. The best overall survey of the period, by Michael Vickery, estimates 750,000 excess d**hs in the Khmer Rouge era from all causes (including starvation and disease resulting from the terrible early postwar conditions), on a population base of six million to eight million. Furthermore, a significant fraction of the several hundred thousand executions occurred in 1978, as part of an internal struggle in which the Pol Pot faction k**ed a great many alleged supporters of Vietnam. Mr. Nordland's review is based on an implausible and ridiculous myth. His further a**ertion that Noam Chomsky attributed the d**hs of the Pol Pot era to ''nothing but'' a war-induced famine is an outright lie. Mr. Chomsky (and the present writer, who was co-author with Mr. Chomsky of his published works on Cambodia) went to great pains to stress that there was no doubt that the Khmer Rouge was committing serious crimes, although we took no position on their scale (which was very uncertain at the time). We focused mainly and openly on the uses to which the West was putting the Khmer Rouge terror, the removal of history and context, the serious distortions of evidence and the selectivity of attention. These were perfectly legitimate subjects in themselves, justified even more by the fact that the West wasn't even proposing doing anything useful for the victims, and by the sequel in which the ousted Pol Pot was quietly rehabilitated as a Western ''freedom fighter.'' But in the West, to focus on the distortions and hypocrisies of a propaganda campaign is to become an ''apologist'' for the villains of that campaign. Mr. Nordland's review, which rests on one of the myths of the Pol Pot era as well as a now institutionalized lie about our own work on the subject, shows that our effort was and remains on target. EDWARD S. HERMAN, Philadelphia