Yeah, usually the Lizard people select world leaders from different clutches of eggs to ensure maximum competition and division among the human nations under them. Due to a malfunction in one of the incubators, Nixon's egg hatched about seven years after Brezhnevs. During that time the same incubator hatched a separate clutch, among which Nixon was counted, which is why he was allowed to become the US president. Having not grown up together, they were still competitive, but little moments like the moon landing concession still occurred from time to time. Now that might sound unconvincing, but that's only because I'm not an actual conspiracy theorist. I don't have access to the deep lore and twisted logic therein.

Kubrick is that good a filmmaker