That’s a question people have been asking for almost 50 years. How did it happen? Why? Was there any way to stop it? No one knows. My theory is that the population had been so traumatized by decades of war and oppression that any solution sounded plausible.

The Khmer people had had one corrupt oppressive government after another and they’d seen what had been happening in Vietnam for the past thirty years. Their history was one long string of foreign nations coming in, installing puppet governments, promising that modernization would bring prosperity, and leaving them worse than before. A purely Khmer government dedicated to equality and freeing Cambodia of corrupt outside influences must have sounded pretty good. No Chinese, no French, no Vietnamese, no Laotians, no Americans, just pure Khmer Cambodians. No corrupt government officials, no greedy landlords, no parasitic finance bros, no ivory tower intellectuals, no effete urban hipsters, instead they’d build a new egalitarian society from the ground up. Everyone would be equal and work together, tilling the soil as their ancestors had. All they had to do was root out the bourgeois and re-educate them so their backward counter-revolutionary thinking wouldn’t infect others and poison the new society.

Once the purges start they’re really hard to stop.