The nuke stuff is actually part of the Trotskyism. Posadas simply adheres to nuclear realism, a concept that was common among all kids of mid-century trots. Trot circles believed that both the yanqui imperialists and the "deformed worker state" USSR were so corrupted that nuclear war was inevitable, a materialist necessity. Posadas just combined that with flying saucers.

a bit jumbled on the chronology, but it's still good and works fine