Was Sauron guaranteed to win in a struggle for control of the Ring?

Question

Leaving aside the quest to destroy the ring; but rather approaching the war from Sauron's perspective: is the winner of the conflict already pretty much guaranteed?

Sauron always assumed that a powerful individual would attempt to claim ownership of the ring to overthrow him. From a game theory point of view this plan seems to have had far greater guarantee of success. The reasons voiced by those powerful enough to achieve this end (such as Gandalf and Galadriel) was that that course of action would replace Sauron with a new dark lord; which, unlike Sauron, had control of the ring and all that that entailed.

So if we are to go with this line of thought Sauron is doomed from the start - very quickly in the narrative his servants fail to prevent the ring from being appropriated by powerful individuals such as Aragorn, Elrond, and Gandalf. While the fellowship's passage east was perilous, such perils were presented by Saruman and the Balrog of Moria, maiar who would likely have claimed the ring had the fellowship been defeated. When eventually Sauron sees Aragorn present himself before the Black Gates with his token force, Sauron assumes that this is the moment of a clash of wills for possession of the ring and bends his entire might (and all of his conscious focus) upon this conflict. Though Aragorn's force was not significant, presumably had Aragorn succeeded in dominating the Ring, it would be game over for Sauron.

Or would it?

Was Sauron guaranteed victory in a struggle (either immediately or ultimately) for control of the ring against an Aragorn or Saruman? We already saw a powerful man (Isildur) claim the ring for himself, with notably poor results. If the odds of such a contest were stacked in Sauron's favour, presumably he had little to fear, and no need to risk much in a war for the ring?

While we (and most of the characters) can only guess at the answer to this - one character who surely would have known the likely winner in such a conflict was Sauron himself. So are his actions one of a desperate player throwing everything he has against the enemy with the world's only super weapon, or dark lord merely killing time before his apparently inevitable success?

Answer 1

Tolkien answers this obliquely in Letter 246, where he imagines an ending to the story where Frodo successfully claims the Ring and confronts Sauron:

[A] confrontation between Frodo and Sauron would soon have taken place, if the Ring was intact. Its result was inevitable, Frodo would have been utterly overthrown: crushed to dust, or preserved in torment as a gibbering slave. Sauron would not have feared the Ring! It was his own and under his will. Even from afar he had an effect upon it, to make it work for its return to himself. In his actual presence none but very few of equal stature could have hoped to withhold it from him. Of 'mortals' no one, not even Aragorn.

^{The Letters of J.R.R. Tolkien 246: To Mrs. Eileen Elgar (draft). September 1963}

In fact, this is the entire point of the plan, as Gandalf describes it (emphasis mine):

We must push Sauron to his last throw. We must call out his hidden strength, so that he shall empty his land. We must march out to meet him at once. We must make ourselves the bait, though his jaws should close on us. He will take that bait, in hope and in greed, for he will think that in such rashness he sees the pride of the new Ringlord: and he will say: "So! he pushes out his neck too soon and too far. Let him come on, and behold I will have him in a trap from which he cannot escape. There I will crush him, and what he has taken in his insolence shall be mine again for ever."

^{Return of the King Book V Chapter 9: "The Last Debate"}

Answer 2

At no time did Sauron act in a way that he thought his victory was a sure thing. He spent time undermining his opponents - subverting Saruman, Rohan via Wormtongue, and Gondor via Denethor.

His strategy was based on moving quickly, even before all his forces were assembled. A strategist would look askance at his attacking Gondor and hoping to assemble his main armies and Southron reinforcements on the battlefield at Minas Tirith rather than wait and attack as one force. As it turned out, he did not have enough force to assure battlefield security and when the Riders of Rohan evaded his blocking force thanks to Ghan Buri Ghan there was no reserve to meet them. The same thing was true of Aragorn's attack from the boats - proper reserves would have made such attacks far less successful.

So rather than the confident move of a force with decisive superiority, we have an army that needs fifth columnists to get a momentary edge, requires the cover of a magic cloud of darkness that can't be maintained long to work at full efficiency, bound to a risky strategy to decapitate Gondor's leadership by taking its capital by a quick "blitzkrieg" strike. It might have gone down in the books as a bold stroke if it had worked, but once the initial strike failed the weak strike force was exposed on the far side of an unfordable major river and cut to pieces.

Answer 3

In addition to @JasonBaker's answer, you can find the following lines in the Ainulindalë:

But when the Valar entered into Eä they were at first astounded and at a loss, for it was as if naught was yet made which they had seen in vision, and all was but on point to begin and yet unshaped, and it was dark. For the Great Music had been but the growth and flowering of thought in the Tuneless Halls, and the Vision only a foreshowing; but now they had entered in at the beginning of Time, and the Valar perceived that the World had been but foreshadowed and foresung, and they must achieve it.

^{_{Silmarillion "Ainulindalë"}}

One can infer that whatever events happened in the world after the Great Music was sung were pre-determined.

Sauron could (should?) have known this, since he participated in the singing as one of the Ainur. Maybe, the music did not show individuals, so he might not have known which part of it was related to him. Or might not have cared enough, being evil and twisted.

Answer 4

Sauron believed two pivotal faces (both untrue as it happens and indicative of Sauron's limited place in a much greater hierarchy). The first was that he had stepped into Morgoth's shoes (or had even become Morgoth returned). The second - and more important - was that Eru had lost interest in Arda. In fact, Sauron has overstayed his time and Eru's plan for His Creation moved inexorably on. The ages in which supernatural beings of great power (and Sauron was one) had a present and tangible presence in the world were drawing to a close. The ages of men were about to begin and men - the TRUE supernatural beings in Tolkien's universe - were to shape their own destiny under Eru, being outside the Music and foreknowledge of the Ainur in a way that all others were not. Sauron was a local evil and in the greater scheme of things: a bit player. In short Sauron COULD have won the war of the ring in theory, but it was never going to happen in practice. Where the Valars' scheme to oppose Sauron (the Istari) faltered, Eru's plan never missed a beat (Gandalf being sent back after the Balrog incident), the ring being found by Bilbo, the destruction of the chief Nazgul according to ancient prophecy, and the Second Prophecy of Mandos re. Dagor Dagorath in which Morgoth himself returns as the chief protagonist. In short - yes - Sauron's defeat was predestined although the exact time and circumstance unknowable; but tied into the ultimate destruction of evil and in Eru's timescale, unknown to Vala, Maia, Elf, Dwarf or man. The die has been cast: the Satanic rebellion of Morgoth and Sauron is self-devouring and its end assured.