the scope of sacrifice

[Marileangorifurnimaluim]

"in lotr, the sacrifice and the willingness of frodo, aragorn, galadriel, elrond and many others have whipped up an inexorable tide towards the death of evil."

First I have to point out that Tolkien said the end of the ring and of Sauron was not the death of evil, even in middle earth. Gandalf pointed this out in the RotK, when he mentioned Sauron was but a servant of Morgoth, (meaning that you'd think the end of evil would come with the defeat of Morgoth, but that was not the case, there was ever more evil to arise).
It wasn't even the end of Sauron, though it seemed unlikely that he could ever rise again.

So Tolkien doesn't point to an ultimate end of evil, but rather to it's constant defeat - by sacrifice, yes - in endless smaller battles.