A dominant civilization keeps weaker races pacified not by force but by granting each a narrow, carefully bounded freedom that feels like autonomy while foreclosing real change. The sense of being free is itself the mechanism of conformity, because contentment within assigned limits removes the motive to challenge them.
A galactic order assigns each species a single function it performs supremely well while depriving it of the others, so that no race can survive alone and all remain locked into the whole. Mastery in one dimension is purchased at the price of helplessness in every other, making excellence a leash.
The moral character of a civilization is read not from how it treats its favored members but from the existence of a despised or excluded group that the system quietly requires. Looking for who pays the hidden cost reveals the real structure that official harmony conceals.