Gondor and
Rohan, and
Arnor before them, are polities whose existence stems from honor and loyalty. Their continued survival depends upon the continuation of honor and loyalty.
Take Arnor, for instance. The princely lines in Cardolan and Rhudaur rebelled against the king, establishing daughter
kingdoms, lesser principalities, in competition with it. The Hillmen eventually took control of Rhudaur and allied with
Angmar, annihilating the Dúnedain remaining within its borders (possibly assimilating some to Angmar, if one ventures to guess at
Faramir’s vague hints to
Frodo and
Sam). Cardolan survives longer, realigning itself with the king in Arthedain; but in the end the whole edifice collapses (including Angmar) because of the selfish disloyalty of two lines of princes a millennium earlier.
Castamir rebels against Eldacar, and his adherents abscond to
Umbar with the Gondorian fleet. These rebellious Dúnedain do not thrive in Umbar: they are absorbed into the greater body of inhabitants (who include descendents of the
Black Númenóreans from a millennium-and-a-half before). Umbar itself might have thrived (and seems to have done so), but the
Númenórean character of its people is greatly diminished: they cease to be
Númenórean (i.e., Dúnedain) and become “
Corsairs of Umbar.”
The same is true in Rohan as in Gondor. There are rebellious lords – Freca and his son Wulf, for examples – and treacherous counselors –
Gríma Wormtongue is the best exemplar of this. But by and large, the
Rohirrim stand by their loyalty and their honor.
Aragorn’s praise to
Merry of dead
Théoden King reveals what holds these polities together: “[H]e was a gentle heart and a great king and kept his oaths.” It reflects Théoden’s speech to his knights before he led the charge on the Pelennor: “[T]hough you fight upon an alien field, the glory that you reap there shall be your own for ever. Oaths ye have taken: now fulfill them all, to lord and land and league of friendship!”
These polities are not
pure: the
Tower of Cirith Ungol was taken by “treachery”: someone yielded up the tower to the
Nazgûl, resulting in its capture. Consider the
First Age instance of Gorlim the Unhappy, who betrayed Barahir and the outlaws of Dorthonion. But this was by far the exception rather than the rule.
At the height of its imperial power midway through
the Third Age, I don’t doubt that Gondor possessed a reasonably complex administrative system that, were the bureaucrats so inclined, would have provided considerable opportunities for graft and corruption. But this would imply that Gondor itself had begun to rot from within, turning its back on its Númenórean past, something that doesn’t seem to have happened even at the end of the age.
Númenor itself, however, is another matter. Shortly after its participation in the War of the
Elves and
Sauron at the end of the seventeenth century of the
Second Age, a shadow fell on Númenor during the reign of Tar-Ciryatan. By the time of his great-grandson, Tar-Telemmaitë, whose recorded name may be a pseudonym because of his love of
mithril (
Telemmaitë, “Silver-handed”), it seems power began to slip from the ruler to his counselors and administrators; and in any case, greed begets greed. I think by this time or soon after, as the
Númenóreans increasingly began to turn their backs to
Eru and to the
Valar as his regents in
Arda, the probability of corruption among the
Kings’
Men increases. It is among
the Faithful Númenóreans, whose states Arnor and Gondor survived into the Third Age, that honesty and decency seem to have continued.