I first went to war when I was 23 years old. I was leading my platoon of light infantry on a run through the woods of Fort Drum, New York, when the first plane hit the World Trade Center. In the months that followed, my infantry company deployed first to Kuwait and then to Afghanistan, where we participated in Operation Anaconda, the last big battle in the conventional phase of the struggle for control of that country. I returned from that battle and joined the U.S. Army’s Ranger Regiment, which fought in both Iraq and Afghanistan. Since leaving the Army in 2004, I have had some time to reflect upon my own experiences while studying other conflicts and serving as an occasional adviser to a succession of commanders in Afghanistan.

A person’s experience in combat is sui generis. We all march into battle from different backgrounds, social classes, and regions. We come from different families, received different levels of education, and developed different expectations. It is difficult to draw broad conclusions about personal experience with—and in the aftermath of—conflict because each and every one of us sees war through our own lens.

Trying to generalize about the experience of combat amounts to, as the author of Ecclesiastes might have put it, striving after the wind. In this sense then, Karl Marlantes’s What It Is Like to Go to War is a failure. It never lives up to its title.

But Marlantes fails brilliantly. For the vignettes and observations in this book will ring true for all of us who have gone to war. And for its wisdom and wit, I recommend it to any young warriors about to deploy to Afghanistan—or journalists or aid workers trying to wrap their heads around their experiences in Libya, Somalia, Syria, and other garden spots on the planet. In order to understand, though, why this book fails and why it is also worth reading, we must start with an understanding of why each combat experience is unique—and the key variables that determine this inimitability.

The first and most obvious variable in the experience of combat is the individualized nature of the combat itself. This variable is entirely and uniquely shaped by local conditions and varies from day to day, from unit to unit, and from place to place. Everyone always remembers the horror of Omaha Beach, but on the same day a few miles to the west, U.S. soldiers landed without much incident at Utah Beach. A soldier from the 1st Infantry Division, then, has a different memory of D-Day than a soldier from the 4th Infantry Division.

Likewise, a light infantryman in the Arghandab River Valley in Kandahar province in the summer of 2010 had a different and more violent experience than a light infantryman in the same valley this past summer. But even these experiences differed from those of soldiers in other units serving in the same area at the same time. Both of these riflemen’s experiences were likely—but not necessarily—more intense than those experienced by a staff officer a few miles to the southeast at the airfield outside the city of Kandahar.

Karl Marlantes experienced war as a U.S. Marine in Vietnam. In 1968, the Yale graduate and future Rhodes Scholar found himself in charge of 40 young Americans in the kind of maddeningly difficult counterinsurgency fight described as “the graduate level of warfare.” Upon returning home, Marlantes spent 30 years working on a novel based on his experiences, Matterhorn, which last year was a New York Times bestseller and has already entered the pantheon of great literature about the conflict in southeast Asia.

Given the remarkable memoirs and novels already written about Vietnam, one might question what another novel had to contribute to the genre. Marlantes found a way, through Matterhorn, to open a new window on both the horror and drudgery of counterinsurgency warfare fought by light infantrymen in double- and triple-canopy jungles. His protagonist, Lieutenant Mellas, clearly the mimesis of Marlantes himself, goes to war full of ambition, but ends ups simply trying to hold both himself and his platoon together. Caught between a stubborn enemy and an infuriating higher headquarters, Mellas and his men fight for themselves.

After four decades, though, Marlantes has more to say about war than one piece of fiction allows. What It Is Like to Go to War is his nonfiction meditation on war as an experience and man’s innate warrior nature. Organized into themed chapters—“The Enemy Within,” “Guilt,” etc.—What It Is Like to Go to War draws from warrior fiction, military history, religious texts, and the author’s experiences to elucidate war and the warrior spirit for the uninitiated.

War, Marlantes argues, offers young men “raw life: vibrant, terrifying, and full blast. We are lifted into something larger than ourselves. If it were all bad, there would be much less of it, but war simply isn’t all bad.” Here Marlantes echoes Robert E. Lee, who, looking down on the carnage of Fredericksburg, remarked that “it is well that war is so terrible—otherwise we should grow too fond of it.” War is an intoxicating, exciting experience punctuated by moments of sheer terror and episodes of soul-wounding loss. How we should harness the warrior spirit alive in man while preparing him for the highs and lows of the experience itself is the central question in this book. Marlantes suggests demystifying the warrior spirit that dwells within us in the same way we now speak frankly with our children about sexuality. “Natural aggression,” he writes, “like sexuality, can either be repressed, to eventually emerge ugly and out of control, or it can be guided into healthy and productive uses.”

Such is the cornucopia of anecdotes and analogies buried within the chapters that it is difficult to identify one or two themes that emerge from the book. Marlantes has much to say, and though each of the chapters has a theme, not all of them are organized as coherently as they could be. As soon as Marlantes begins to discuss a particular theme, for example, he gets distracted by a story from his own past that pertains to the subject matter. The strength of the book is that the author has such vivid stories to tell, but those stories can also be a weakness because they necessarily make his arguments personal rather than general.

The reader senses Marlantes is a man with many stories to relate—with many stories he needs to relate. I understand this. I teach and lecture frequently on irregular warfare, and it is rare that I lecture on the theme without mentioning my own experiences in Iraq and Afghanistan—to say nothing of the time I spent as a civilian researcher in Lebanon.

In my own family, young men on my mother’s side are more or less expected to serve in uniform. As our family has become more wealthy and educated over the past two generations, that expectation has remained constant. My grandmother gave birth to three daughters, all of whom expect the men in the family to match their own father, a veteran of the Pacific campaign, in terms of military service. In fact, when I called my mother on the eve of my first deployment to war, she greeted me first with silence and then coldly warned me, “Well… don’t embarrass your family.” (“I love you too, Mom!”)

Most American men and women do not grow up with similar expectations. Judging from the way in which U.S. service members are themselves often the sons and daughters of veterans, however, the U.S. military is different from American society as a whole, and that might explain some of the remarkable resilience of the all-volunteer force after a decade of war.

There is a dangerous narrative developing out of the wars in Iraq and Afghanistan that all soldiers and Marines suffer from some kind of post-traumatic stress. My colleague Meg Harrell, who leads our program on veterans and military families at the Center for a New American Security, has studied the ways in which U.S. corporations blanch at the thought of hiring veterans because of the worry that these men and women are somehow scarred by their service. This is not necessarily true. Many soldiers or Marines, me included, have suffered no ill psychological effects from our service. I have no idea why some suffer from post-traumatic stress and others do not. I can only speak to my own experience.

Why have I not suffered from being in war? I can only hazard guesses. I was born and raised in the mountains and valleys of East Tennessee. My family has owned the same farm in northern Hamilton County for two centuries, and one of my ancestors led North Carolina’s militia during the American Revolution. East Tennesseans are, generally speaking, kind and God-fearing mountain people. During the Civil War, though, we waged partisan, guerrilla warfare against both outsiders and ourselves with a brutality that horrified Union and Confederate commanders alike. Set against one another, we killed our cousins and erstwhile friends with both cunning and terrifying violence. We are, in other words, the Americans perhaps best suited, psychologically speaking, for combat in the mountains of Afghanistan. The only differences, perhaps, between the Taliban of Afghanistan and the Presbyterians of East Tennessee is that the former are both far poorer marksmen and more tolerant toward the Roman Catholic Church.

When I deployed to combat, I experienced it first at the head of a tight-knit platoon that had bonded for five months in the deserts of Kuwait before ever hearing a shot fired in anger. I then experienced combat alongside some of the best-trained and specially selected warriors in the U.S. military. In each deployment, I led and was supported by noncommissioned officers who are still close friends, and was in turn led by commanders who remain valued mentors to this day. I know the parents, wives, and children of the men I led into combat. I know the parents, wives, and children of the men who led me into combat. We were a family, and we experienced war as such.

My combat experiences were perhaps more intense than most soldiers’ and Marines’ but certainly not as intense as those of others. I saw many men killed and killed a few myself, but I lost no close friends and never lost any solider or Ranger under my leadership. I deployed three times with a collection of young men, waving goodbye to their wives and children, and then returned them to those same wives and children months later. Only one of my soldiers was ever seriously wounded, and we managed to evacuate him without incident.

I sometimes wonder, though: What kind of man would I be had I experienced war as so many of my close friends did, as company commanders and Special Forces team leaders in Iraq in 2006 and 2007? How would I have responded to the inevitable deaths of men under my command? What if I had been seriously wounded myself? The only physical injury I ever experienced was a broken leg sustained in a hockey match between some of the officers in my unit. A few years ago, I visited Walter Reed Army Medical Center in Washington to see a young man who had succeeded me as the leader of my old light infantry platoon. He was missing one leg below the knee and an arm below the elbow. After an IED had exploded in Iraq, one of my friends, now this young officer’s platoon sergeant, had gathered his broken body up into his arms and run a kilometer to the Medevac helicopter. What if that young lieutenant had been me?

Marlantes never really explains what it is like to go to war. He cannot. What Marlantes can do is explain to his reader what his experience was like and how he went on to process his formative experiences over the next four decades. He laments that “the Marine Corps taught me how to kill, but it didn’t teach me how to deal with killing.” Marlantes believes we can and should do a much better job preparing our young men and women for dealing with the experience of combat, even if he explicitly states his book is not intended to “fix” military training. He believes veterans need to tell their stories. Like the Navajo warrior of old, they need to sing of their adventures in order to return home into the fold. “This book,” Marlantes tells us, “is my song.”

Marlantes stresses the fact that war is a phenomenon that has endured throughout human experience, as well as his belief that it should be treated as something separate from or special in relation to that broader experience. A Calvinist, though, would argue that war is simply another manifestation of our fallen, sinful condition. And a Clausewitzian would invoke the famous quote that war is simply “a continuation of political intercourse, with the addition of other means.”

There is nothing, perhaps, all that special about war itself. War, as a phenomenon, is normal. There is something special about the unique stories of the men who fought, though. Marlantes tells many stories in this volume, most of which are written with great eloquence, and with humor and humility. These stories—and the lessons contained in them—are what give this book its worth. Younger veterans and soldiers who read this book will not recognize their own experiences in those of Marlantes because their experiences are unique. But much of what Marlantes did and has gone on to observe will resonate for those who have seen combat, and the process he went through to grow at peace with his experience contains valuable counsel for men and women who followed him into the Temple of Mars.