Scary Dogmatic Aliens: Mostly averted, inasmuch as despite all the wide intellectual, cultural and biological differences between species, most of them aren’t blessed with an overwhelming urge to bring it forcibly to the rest of the universe.  Well, no more so than, say, 21^st-century humans, anyway.

Played straighter by, say, the skrandar (of the Aliens as Nazis type, had the Nazis been into building berserker probes, inasmuch as they wanted all sophont life other than them destroyed); the Leviathan Consciousness (of the Aliens as Communists type, had the communists been motivated by the desire to save energy by eliminating redundant thought processes), and, in a twisted and non-expansionist sense, the Equality Concord, although what the Equalitarians have done to themselves scares the crap out of everyone; the Theomachy of Galia (of the Aliens as Religious Fundamentalists type, except they’re not so much Scary Dogmatic Aliens as Laughable Dogmatic Aliens, being a standing joke to all more sensibly organized polities – and when I say more sensibly organized polities, I’m including the space fascists and the Interstellar League of Tribal Chiefdoms); and the Trikhad Conquest (of the Aliens as Conquistadores type, as the leading member of said notional League – although again, generally closer to Laughable Dogmatic Aliens, given how well interstellar colonialism usually works).

Most of the Great Powers with definite ideologies tend to be seen this way, too, just because power is scary; including the Voniensa Republic (who are certainly smug enough and unashamed about their desire for ideological promulgation, even if about as good at doublethinking this as the modern Terran West) and the Empire (who are at least as smug, but at least in the public sector are for the most part publically self-aware about the paradox inherent in “conquering for freedom”).