The Daily Kos has a great entry (by Billmon) this morning about the wartime imagery in The Two Towers. Billmon explores in detail the parallels -- vigorously denied by Tolkein -- between war in Middle Earth, WWII, and even 8th Century Europe. Tolkein argued against the "modern day allegory" interpretations of his works, but it's nonetheless possible to see reflections of the times in his Middle Earth.
I confess to being a little uncomfortable with some dialogue in The Two Towers. Lines like (paraphrasing), "Whether we seek it or not, this war has come to us," imply the inevitability of war that is, in Middle Earth, waged between the purely evil and the purely good -- the good descended from races of kings. Billmon points out that our present possibilities of war are much more complex, irreducible to simple good and evil or any kind of moral absolutes.
In a very real sense, a mythology of who "we" are versus who "they" are has been invoked; when Bush spoke at Ford Hood last week, he reminded us that we are fighting for freedom and goodness, against irrational and tyrannical dictators. But that kind of rhetoric makes it hard to simultaneously argue that "America is a friend of Islam." As Billmon suggests today, we have to allow the conflict to be far, far more complex than that.
Aside: Be sure to read the comments to Billmon's entry: They are equally thoughtful, and tend to stress that Tolkein allowed, in many ways, for the wars of Middle Earth to be complex: They are about power that corrupts, fallibility of both sides, and redemption. The problem doesn't lie with what Tolkein actually wrote, but with present-day interpretations that would deny the complexity of his story.