Expert witness professor Alexander Hinton, author of Why Did They Kill?: Cambodia in the Shadow of Genocide, testified at the Khmer Rouge tribunal yesterday on the social and political factors that led to the perpetration of alleged crimes under the Democratic Kampuchea regime.

Defendants Nuon Chea and Khieu Samphan are being tried on charges of genocide against the Vietnamese and the ethnic Cham in the current Case 002/02, and Hinton, an anthropology PhD who holds the UNESCO chair on genocide prevention at Rutgers University, yesterday expounded on his model of “ideological genocide”, which he argues fits the Cambodian context.

“One of the ‘primes’ you find in virtually every genocide is some sort of socioeconomic upheaval,” Hinton told the court, explaining that in 1970s Cambodia that prime could have been the conflict in neighbouring Vietnam “and waves of upheaval that were linked to that”, such as the US bombing under Operation Menu and the 1971 coup.

“In situations of existential angst people tend to gravitate towards messages that are clear, simple and – amidst the chaos of upheaval – a vision of a better world,” Hinton continued, pointing to the national emblem of Democratic Kampuchea, which depicted a sort of agro-industrial utopia, as an embodiment of such a vision.

Another factor, Hinton continued is “the manufacturing of difference” – the process of separating targeted groups like the Vietnamese and Cham from the general population.

An example provided later was the use of terminology in propaganda such as “rats, running dogs, germs” to dehumanise, which reduces the “moral inhibition” to killing those victim groups, Hinton argued.

Throughout the day prosecutor William Smith presented Hinton with excerpts of Khmer Rouge radio broadcasts and publications such as the Revolutionary Flag magazine, which Hinton repeatedly affirmed as contributing to the genocidal process and the “moral restructuring” which constituted the “revolutionary consciousness” of the Khmer Rouge.

“It lays out target groups against which violence can be perpetrated,” Hinton said of the propaganda, adding “these are precisely the sorts of [categorisations] that you find being used by many groups, [like] ISIS today . . . language of finding the other that needs to be eliminated”.

More than once, Nuon Chea defender Victor Koppe objected to Hinton’s liberal use of terminology, and questioned whether – “being an anthropologist” – he actually had the expertise to shed light on the evidence.

“My client downstairs is quite upset with things that he heard from his holding cell . . . carelessly using the word[s] ‘genocidal regime’ and ‘genocide’. I find that way outside of the scope of the expertise also, of this . . . expert,” he said.