I've recently become interested in the Khmer Rouge and one thing that I'm struggling to make sense of is exactly where I would put them on the political landscape. On one hand, I know they were allied with the USSR and certainly self-identified as communist, however, a lot of their stated beliefs seem a lot more like fascism - ethnic nationalism, nostalgia for a lost great past, focus on agricultural production as opposed to industry, and other things that I typically associate more with the far Right then the far Left.
They weren't exactly singing "Workers of the World."
It seems like, in many respects, they combine the worst of state-communist and fascist ideologies. How do historians and political theorists talk about this? I always learned that Pol Pot was just another communist dictator, but it seems like there's a bit more going on than that.
If anyone has any interesting readings on the Khmer Rouge as an ideological movement, or a good biography of Pol Pot, I'd take a recommendation. Most of what I can find is first-person accounts of things like the Killing Fields. Tragic, but more personal narratives and autobiographies than political.
Historians characterise the Communist Party of Kampuchea as a Marxist-Leninist-Maoist inspired regime, albeit one with xenophobic, nationalist and autarkic aims. You might like a few of the answers that I have written here which address your question:
Was Pol Pot Inspired by the French Revolution?
As for further reading, if you were only going to read one book on the Khmer Rouge I would recommend Philip Short's biography of Pol Pot "Pol Pot: History of a Nightmare". You might be interested in the podcast that I produce called 'In the Shadows of Utopia'. Perhaps 'left wing' and 'right wing' are not descriptive enough points to colour many of the 20th century's political movements, perhaps different themes, motivations and policies span all kinds of the political landscape without fitting into the kind of framework you suggest. As for what the KR 'really believed', I think there are plenty of examples in their rhetoric that confirm what their ideology was. They were not shy in advertising their aims and motivations, and they certainly believed in revolution, perhaps most importantly the 'super great leap forward' that the CPK presumed would progress Cambodia from an agrarian economy into an industrial one. But all of this is outlined in those other answers.
Correction: They were allied with the People's Republic of China, not the USSR. By the late 1970's, Vietnam was much more allied with the USSR than China, while Democratic Kampuchea was the opposite- viewing the USSR as being revisionists and not true communists. This culminated in the Third Indochina War between Vietnam and the PRC following Vietnam's invasion of Democratic Kampuchea.
Pol Pot's actions and the Cambodian Genocide were inspired by the Cultural Revolution in the PRC, which used similar tactics, albeit not at the same scale of brutality as under the Khmer Rouge. The PRC was much more extreme by this point in time than the USSR was, which motivated the earlier Sino-Soviet split.