"None of the characters, as Tolkien wrote the story, really understands the whole of what is going on.
"Not even Gandalf. In fact, the only thing they do know is that their fate will not, in the end, be determined by visible events but by a mostly invisible one: the stealthy crawl of three insignificant-looking characters into the lion's mouth of Mordor.
"The great ones and the heroes are continually trying to see what is happening elsewhere, through the palantirs and the Mirror of Galadriel and the Eye of Sauron. The attempt is repeatedly disastrous. Denethor commits suicide because of what he sees in his palantir, but he has read it wrong. As Gandalf says, "Even the wise cannot see all ends," and the really wise remember that.
"The moral is the motto of the British redcoat: "Look to your front." Don't think about what other people are doing: you'll get it wrong and it's disheartening. Or, to quote Gandalf again - and Jackson picked out just these words to repeat in the first movie, varying the pronouns cunningly - "[The future] is not for us to decide. All we have to decide is what to do with the time that is given us."
"Tolkien surely did not mean these words just for Frodo. They were a major part of his own conviction and a part of his own cure for the defeatism, the appeasement, the lack of will and the weary calculation of odds that he saw dogging the Western democracies as he was writing The Lord of the Rings and still after he had finished it.
"Tolkien's achievement, it may be, was to reintroduce a heroic world view, drawn from the ancient texts he taught as a professor, to a world gone ironic."