I do not think anyone here will argue against the ideal, nor that we are under an obligation to do what we can to realize it, but that vast majority of history involves nations that were very far from realizing, or even knowing, that ideal. Some prospered, at least to whatever degree they could -- full of imperfections as they were. Or, would you argue that there has been no real prosperity, even from a purely natural point of view, in any non-Catholic nation? Was the prosperity of Rome, for example, an illusion? Certainly, it was far from perfect, even in its better days, but does that mean the leadership of Rome did not even possess the "right or ability to govern justly"? St. Augustine posits the idea that the government of the world was given to the Romans as a reward for their truly notable virtue, limited to the natural sphere though it was.
I see this discussion as analogous, in some ways, to the discussion of the relationship between nature and grace. While grace is infinitely superior to nature, nature, even fallen nature, is not completely worthless, etc.