I think it was sort of meant to be a check on the middle powers: sure, you could do some war / genocide, but we have a legitimately-sounding system of rules by which superpowers can punish you.

In practice, superpowers don't apply these rules consistently because it's sometimes in their geopolitical interest for a subjectively less-bad option to win by any means necessary, and they don't hold themselves to the same standard... so yeah, it does end up being a bit of a fantasy.