>” It's more that they spent the entirety of the Cold War period propping up any dictators they could find as long as they weren't communists, and it usually backfired.”
But the Khmer Rouge were the communists! They were officially the “Communist Party of Kampuchea (CPK)”.
Yeah they supported the right-wing dictator that deposed the king who then joined Pol Pot and enabled his rebellion to succeed. And policy shifted after the 70s when they decided communism was ok, as long as you opposed the USSR. This was the justification for normalizing relations with China, who wound up supporting the Khmer Rouge, since they opposed post-war Vietnam (who they had just supported in the Vietnam War), which was a USSR ally.
It was a complicated time to be deciding who to coup.
But the Khmer Rouge were the communists! They were officially the “Communist Party of Kampuchea (CPK)”.