At the end of the day, we have to ask what is the point of worldly glory in the first place? Is it not better to be poor and content than rich and always worried for your own wealth? In the same way, isn't it better to be a small-but-satisfied state than to pursue greatness, always knowing that it is the way of the world that your greatness will pass?
Even having wicked rulers is no great calamity, since it merely provides a place to test our faith and virtue.
This chapter is good enough to stand on its own, with no comment:
Justice being taken away, then, what are kingdoms but great robberies? For what are robberies themselves, but little kingdoms? The band itself is made up of men; it is ruled by the authority of a prince, it is knit together by the pact of the confederacy; the booty is divided by the law agreed on. If, by the admittance of abandoned men, this evil increases to such a degree that it holds places, fixes abodes, takes possession of cities, and subdues peoples, it assumes the more plainly the name of a kingdom, because the reality is now manifestly conferred on it, not by the removal of covetousness, but by the addition of impunity. Indeed, that was an apt and true reply which was given to Alexander the Great by a pirate who had been seized. For when that king had asked the man what he meant by keeping hostile possession of the sea, he answered with bold pride, “What thou meanest by seizing the whole earth; but because I do it with a petty ship, I am called a robber, whilst thou who dost it with a great fleet art styled emperor.”And, just for fun:
If we want evidence for this, we can look at both the bad men who have been Emperor and the slaves and gladiators who have escaped and risen to great heights of power. Great power and majesty in the world does not make one good and does not imply Divine favor.
We can also look for evidence at the general pattern of the nations of the world, including Assyria. What we see is that nations grow on the backs of their oppressed neighbors, with injustice at the root of their expansion.
Whether we're talking about its leadership or its expansion, Augustine's point here is that the city of man is shot through with sin and must be neither romanticized nor glorified.