Cambodian officials say that changes to new textbooks which gloss over the murderous policies of the Khmer Rouge are in the spirit of forgiving and forgetting.
But educators insist that obliterating the past in this way is akin to a "national exercise in forced ignorance".
Since 1991, when the Khmer Rouge signed a peace agreement with other Cambodian factions, references to the horrors of the regime have been expunged from new Cambodian textbooks for use in primary grades, under orders from the education ministry.
But recently teachers were instructed to discontinue lessons on the subject in higher grades, replacing it with instruction on the environment, morals and human rights.
A spokesman said that the government "was carrying out a policy of national reconciliation and would like to see that such subjects as Khmer Rouge atrocities be removed from the education syllabus".
Stories of the genocides carried out by the Khmer Rouge, led by Pol Pot and the recently rehabilitated Ieng Sary and Khieu Samphan, have been included in secondary school textbooks, which portrayed the three Khmer Rouge leaders as traitors. But now that Ieng Sary is part of the government coalition, his role is expected to be reviewed.
Cambodia's Education Minister Tol Lah said he would not rewrite history and that the main issue is not whether or not to teach the history of the "killing fields" but from which grade it should be taught.
Curriculum specialists say new texts for secondary grades are likely to include basic information such as the numbers killed, but details of how so many were executed or died as a result of starvation, torture and forced labour will not be included.
However, many teachers say it is unlikely that schoolchildren will be allowed to forget the past as long as there are still so many survivors of the Pol Pot regime.