A little while ago, Ilya Somin at the Volokh Conspiracy wrote a brief but interesting review of the new Tolkien novel The Children of Hurin. One statement stood out to me as especially interesting:
The story also emphasizes Tolkien's view (perhaps influenced by his experiences in World War I) that waging war against evil often requires time and patience, avoiding both premature defeatism and premature large-scale offensives.
I don't know whether this is accurate to Tolkien's intent, but I thought the ensuing discussion in the comments was very helpful in terms of why he takes Tolkien this way. But what's perhaps more interesting to me is that this seems like a perfectly normal use of the word 'evil', one that assumes nothing in particular about the metaphysical or moral content of the term. Speaking of fighting against evil in this sense does not involve any assumption about some force of evil in the world, never mind about whether such a thing is as powerful as any good force.
It amazes me how many philosophers I know think that using 'evil' as a noun in this way somehow reveals a hidden Manicheanism or dualism in one's view of good and evil (i.e. the view that good and evil are equally powerful forces). Sometimes the claim is put that President Bush is "ontologizing evil" by using the word 'evil' as a noun in this way, which is philosophical shorthand for the same point. A friend of mine called me up last week for other reasons, but the conversation degenerated to a series of his gripes against some of the views I've argued for on this blog that he'd been holding in for a couple years and had to get out before he leaves town (at least that's what it seemed to me he was doing), and at one point he just couldn't fathom how I could possibly think President Bush is not a dualist of this sort given how often he uses the word 'evil' as a noun in this way.
This kind of abstract language isn't all that uncommon. Are people ontologizing cancer as if it's some all-powerful force in the universe when they say that we're forming a crusade against breast cancer? Are Mothers Against Drunk Driving treating drunk driving as some evil force on the level of divinity if they speak as if they're waging a war against drunk driving? Are politicians ontologizing corruption as some spiritual force as powerful as God whenever they speak of fighting corruption? I don't see how it's any different when it comes to fighting terrorism, fighting terror, or fighting evil. It's a credit to the Volokh Conspiracy readers that no one repeated that meme in the comments.