In the 1981 epic medieval fantasy “Excalibur,” director John Boorman warns us through King Arthur’s court magician, Merlin: “For it is the doom of men that they forget.”

But that isn’t true for fiction and nonfiction writer Steven Pressfield, who repeatedly holds up the past as a mirror to our present. 

In his 1998 novel, Gates of Fire, he depicted the heroic last stand of “The Three Hundred Spartans” at Thermopylae.

In Tides of War (2000), he recreated the later conflict between ancient Athens and Sparta through the life of Alcibiades, the infamous Athenian statesman and general.

And in The Virtues of War (2004), he showcased the brilliant and luminous (if increasingly dark and explosive) personality of Alexander the Great, whose soaring rhetoric inspired men to hurl themselves into countless battles on his behalf.

But it is his 2006 novel, The Afghan Campaign, that today holds special relevance for Americans obsessed with the end of their 20-year war in Afghanistan.

The novel opens with Matthias, a young Greek seeking glory and opportunity, signing up with the army of Alexander the Great. But Alexander has conquered the Persian Empire, and with it have passed those conventional, set-piece battles where everyone can instantly tell friend from foe.

Alexander next plans to conquer India. But first he must pacify its gateway—Afghanistan. It is here, for the first time, that the Macedonians meet an enemy unlike any other.

“Here the foe does not meet us in pitched battle,” warns Alexander. “Even when we defeat him, he will no accept our dominion. He comes back again and again. He hates us with a passion whose depth is exceeded only by his patience and his capacity for suffering.”

Matthias learns this early. In his first raid on an Afghan village, he’s ordered to execute a helpless prisoner. When he refuses, he’s brutalized until he strikes out with his sword—and then botches the job.

But, soon, exposed to an unending series of atrocities—committed by himself and his comrades, as well as the enemy—he finds himself transformed.

It is not a transformation he expected—or relishes. He agonizes over the gap between the ideals he meant to embrace when he became a soldier—and the brutalities that have drained him of everything but a grim determination to survive at any cost.

Pressfield, a former Marine himself, repeatedly contrasts how noncombatants see war as a kind of “glorious” child’s-play with how those who must fight it actually experience it.

Steven Pressfield

He creates an extraordinary exchange between Costas, an ancient-world version of a CNN war correspondent, and Lucas, a soldier whose morality is outraged at how Costas and his ilk routinely prettify the indescribable.

The phrase Lucas hates most: “Put to death.”

“Language matters, Costas. Look at my feet. That black isn’t dirt. I can scour my flesh with lye and caustic. That man-blood never comes out.

“I hate the Afghan. He is a beast and a coward. But what I hate most is that he has dragged us down to his level.”

And we know the truth of this exchange immediately. For there are brutalities inflicted by our troops on the enemy—and atrocities inflicted by the enemy upon our soldiers—that never make the headlines, let alone the TV cameras.

We know, though we don’t wish to admit, that, decades from now, thousands of these men will carry horrific memories to their graves. These memories will remain sealed from public view, allowing their fellow but unblooded Americans to sleep peacefully, unaware of the price that others have paid on their behalf.

Like the Macedonians (who call themselves “Macks”), our own soldiers found themselves serving in an all-but-forgotten land among a populace whose values could not be more alien from our own if they came from Mars.

Instinctively, they turned to one another–not only for physical security but to preserve their last vestiges of humanity. Pressfield is never more eloquent than when he puts into the words of his war-weary veteran, Lucas, the following:

“Never tell anyone except your mates. Only you don’t need to tell them. They know. They know you. Better than a man knows his wife, better than he knows himself. They’re bound to you and you to them, like wolves in a pack. It’s not you and them. You are them. The unit is indivisible. One dies, we all die.”

Put conversely: One lives, we all live.

Pressfield has reached into the past to reveal fundamental truths about the present that most of us could probably not accept if contained in a modern-day memoir. These truths take on an immediate poignancy owing to our recent wars in Afghanistan and Iraq. But they will remain just as relevant decades from now, when our young soldiers of today are old and retired.

The Afghan Campaign thrusts us directly into the flesh-and-blood horrors created by political rhetoric: The horrors of men traumatized by an often unseen and always menacing enemy, and the horrors they must inflict in return if they are to survive in a hostile and alien world.