Aragorn's political skills.

[Lyta_Underhill]

All three armies understood that without their respective leaders, they could not have enjoyed what they have acquired. This clientele system was the basis of any great military leader with higher aspirations.

Of course, Aragorn did have the support of the entire Kingdom of Rohan and their legions, as well as the endorsement of the Prince of Dol Amroth, who was to rule as Steward in the stead of Faramir when the latter was injured and in the Houses of Healing. He is also credited with the healing of Faramir, who is beloved of all in Minas Tirith, soldier and civilian alike. I always found it extraordinary that Aragorn, unlike a harsher military leader, did not chastise those soldiers who did not have the heart or strength to fight at the Black Gate, but instead allowed them to save face by turning them to the task of retaking the lands lost in the previous battle. The way I see it, to agree with Neurion above, without Frodo's success, it doesn't matter whether Aragorn is king of Gondor and Arnor or not. But his humanity will still be weighed in the balance, and not be found wanting. He acts in a way that puts humanity above the mere realm of Gondor and in this, reflects Faramir's assertion to Frodo with regard to the Ring, that he would not take it even if Minas Tirith were to fall.

An apt quote of Letter 183 as well, SPM, and there does seem to be a consciousness on Aragorn's part that he must have support; however, that support will not be bought at the price of inhumanity to a single person. It is refreshing to see such scrupulous integrity, and I can understand why it would be astronomically improbable in the "real world." Therefore, I avoid real people and talk to Ents!

Cheers!
Lyta