To call the child fighters of Africa "soldiers" is like calling Auschwitz a detention center: It's factually true, but misses the point. Children have always been victims of war, and child soldiers are not a modern invention. But what we have seen in the recent civil wars in places like Uganda, Liberia, and Sierra Leone is something new. These wars are, first, fought almost entirely against unarmed civilians; they are marked by massacres, not battles. Second, they have no discernible political purpose, unless seizing power, stealing booty, and inflicting terror can be called political, which I don't think they can. (I challenge anyone to define, or even discover, the political program of Sierra Leone's Revolutionary United Front.) Most of all, tens of thousands of children, often in their teens but sometimes younger than ten, have been conscripted into these wars, stuffed with powerful drugs, and repeatedly forced to commit atrocities—including mutilation, rape, and murder—against civilians, other children, and even their own families. At the same time, child soldiers are often, themselves, victims of these crimes, with young girls in particular used as sex slaves by the adults for whom they fight. There is good reason why, given the West's history of colonial exploitation and racism, we hesitate to use the word barbarism in relation to Africa. But in this case that hesitation shouldn't last too long.

The aim of these cruelties, perpetrated against and by children, isn't to win wars; surely there is no military advantage to making a child murder his brother or rape his neighbor. The aim is, rather, to tear these children from any recognizable ethical, familial, and social universe; scramble their personalities through humiliation and terror; bind them through fear, guilt, and even a perverse gratitude to the commanders who enslave them; and, most important, transform them into perpetrators even as they are victims. The aim, in short, is to make these children less than human as the price of survival, and to blur the moral divide between victim and torturer, pushing them into the "gray zone" of which Primo Levi wrote. Several recent books have focused on the perversely intimate nature of this violence. Jimmie Briggs's Innocents Lost: When Child Soldiers Go to War opens with the "choice" presented to François Minani, a sixteen-year-old who, in the midst of the Rwandan genocide, is forced to kill his sister's four young sons by crushing their skulls. Moses, Citizen & Me, a novel by Delia Jarrett-Macauley, tells of an eight-year-old child soldier in Sierra Leone who murders his beloved grandmother, then returns to his shattered family.

Human-rights organizations and various journalists have done good work in describing the phenomenon of child soldiers. Yet it remains hard to understand. Like child prostitutes, there is something counterintuitive about child soldiers: The activity and the age don't mesh, but together they create something that is unnatural and obscene. Moreover, the phenomenon—at least in its current incarnation—turns on its head the long-standing ethos of most resistance movements, including those in Africa, which have traditionally regarded protecting children as one of their highest priorities. Who would have thought that, twenty-five years after independence, Uganda would see the rise of an indefatigable, homegrown group called the Lord's Resistance Army—they dislike bike riding, among other things, and so cut off the feet of anyone caught in this subversive act—which specifically targets children to kidnap, beat, rape, and enslave?

I leave it to others to discuss the likely causes of these wars: the failures of modernity, the toll of colonialism, the burden of poverty. But analyzing the causes of a phenomenon is different from understanding an experience—understanding, that is, not how it came to be but how it lives in the world. With child soldiers this is particularly difficult, since they are both pitiable and odious. Should we turn to the world of imagination to engage this thing, which is undeniably, grievously actual and yet, in its strange horror, seems surreal? Can fiction shed more light than studies from Human Rights Watch or reports from the BBC?

* * *

This is what Uzodinma Iweala attempts in his first novel, Beasts of No Nation. Iweala is a twenty-three-year-old whose parents are members of the Nigerian elite (his mother is the country's minister of finance); he was born in the United States, was raised in a posh Washington suburb, and recently graduated from Harvard. He has said he became interested in child soldiers when, as a high school student, he read a Newsweek article about Sierra Leone.

The plot of Beasts of No Nation is simple and sparse. Iweala tells the story of Agu, a young boy aged somewhere between nine and twelve, who lives in an unnamed West African country. Agu, we learn through brief, wistful flashbacks, was many things: son of the village schoolteacher and a gentle, Bible-reading mother; brother to his sister; best friend to his neighbor, Dike. Agu went to school, where he studied under strict Mistress Gloria, and to church each Sunday, and his home was filled with "many book of different size and different color—some red, some yellow, some blue, and some brown." Agu had a world, and it was good. But it could not hold: "It still is not like we are having time to prepare for this war because everything was still happening so fast. . . . One day, they are closing school because there is no more Government." The situation rapidly worsens as militias threaten to assault Agu's village; women and many children—including Agu's mother and sister—are evacuated by the United Nations (a bit of wishful thinking, that), but Agu stays with his father to protect the village. When the militias—with their "screaming and shouting and laughing"—arrive, Agu's father is killed: "I am seeing bullet making my father to dance everywhere." Agu is captured, beaten, and taken on by the rebel army; the novel charts his travels through his savage new world.

Iweala excels at plunging the reader into the particularly disorienting, irrational quality of this savagery, and thus recalls Primo Levi's depiction of Auschwitz, where, Levi was told, "There is no why here." But whereas Levi used precise, restrained language to describe his hell, Iweala presents violence as a frenzy of demonic energy. Here is Agu's initiation, in the book's first scene:

Again and again he is hitting me and each blow from his hand is feeling on my skin like the flat side of machete. I am trying to scream, but he is knocking the air from my chest and then slapping my mouth. I am tasting blood. . . . The whole world is spreading before me and I am looking up to the gray sky moving slowly slowly. . . . This is making me to think of jubilating, dancing, shouting, singing because Kai! I am saying I am finally dead.

Agu is quickly introduced to the rebel leader—known only as Commandant—who refers to Agu as a "thing" and presents the boy with the choice of joining up or death. (Later, Agu and some other children will obey an order to kill a boy who refuses to fight.) And so begins Agu's life of hunger, fear, and exhaustion, of "the gun shooting and the knife chopping and the people running," of stealing from the poorest and burning down their houses, of raping women and slicing babies from their mothers' wombs, of gulping "gun juice" to ease the pain and fire him up for the next set of atrocities. As the book progresses, Iweala depicts the utter nihilism of this violence: "I am killing everybody, mother, father, grandmother, grandfather, soldier," Agu observes. "It is all the same. It is not mattering who it is, just that they are dying."

Commandant is described as a monster: yellow toothed, black gummed, red eyed. But then again, he is a monster. (Though no more so than real-life counterparts like Liberia's Charles Taylor, indicted for war crimes but living comfortably in exile.) Commandant rallies his boy troops to massacre with the stirring cry "The blood must flow!" He promises Agu that murder is "like falling in love." He takes pleasure in watching his victims humiliate themselves before execution; indeed, laughter is the most sinister sound in this book, since it is heard only in the company of torture and murder. Commandant is a cannibal. And a rapist: not "just" of women but of children and, repeatedly, of Agu. "It is making me to angry and it is making me to sad, the thing that he is doing to me," Agu says. "How much it is making me to want to vomit." Still, Commandant insists, "I am not bad man"—the special plea of bad men everywhere.

Iweala occasionally lapses into sentimentality, as when Agu remembers how, in his village church, "They are always telling us that God is liking children so much." But the author's special bravery is to show us Agu not just as victim but as perpetrator too—and the poisoned high that violence gives him. In one cinematically visceral scene, Agu and his mute friend Strika assault a petrified, praying mother and daughter:

This woman is enemy. . . . And this girl is enemy. . . . We are pulling the girl, pulling until her leg is cracking, but she is not letting go. She is screaming and I am seeing her breath. . . . Then Strika is taking his knife high above his head and chopping and everybody is coming apart.

The girl is having no more hand. . . . I am jumping on her chest. . . . I am jumping on her head. . . . I am liking the sound of knife chopping KPWUDA KPWUDA on her head and how the blood is just splashing on my hand and my face and my feets. . . .

Another night.

Iweala has created a new syntax in which to tell his tale. It is highly impressionistic, almost singsong in its rhythms, and, in its wise simplicity, evocatively suggests the ways in which a child might live through an incomprehensible nightmare. Agu describes his former village: "The village sadding too much because war is taking everything away from us." And his emotional state: "I am not happying anymore. I am not happying ever again."

Yet the more I read, and the more I thought, the less this language made sense and the more annoying it became. Agu is presented to us as highly literate: "I am liking to read so much that my mother is calling me professor," he recalls, and he boasts that he was "the smartest person in my class." Whatever language he spoke—French, English, or one that was indigenously African—he would have mastered complete and grammatical sentences. Why then is he addressing us in this mutant tongue, which verges on a kind of pidgin English? Since there is no organic reason for Agu to speak like this—since, in fact, speaking like this negates the logic of his upbringing—Iweala's linguistic invention becomes a form of stylization: It moves from being an expressive tool to being a gimmick. And when used outside the novel, the effect is even worse, as evidenced by a recent essay Iweala wrote in Agu-speak for the Powell's bookstore website. (Sample line: "In the University, I am learning English well well.") Agu's language, Iweala explained, was an attempt to prevent him from "speaking like white man through his nose and sounding like white man." What white man would that be? Iweala is coming uncomfortably close to self-parody here.

* * *

For all its unrelenting brutality, Beasts of No Nation is a novel of great optimism. In fact, the book is so stubbornly humanistic that I wonder whether it is less a horror story than a fairy tale. And this is because Agu, throughout his travails and despite his degradation, never loses his moral bearings, which is to say his guilt and his torment over his crimes. He continually engages one of the key questions of moral philosophy: Can actions that are coerced be wrong? Certainly he hopes not. "I am not bad boy. I am not bad boy," he promises himself. "Soldier is supposed to be killing, killing, killing. So if I am killing, then I am only doing what is right."

But Agu fails—wondrously, gloriously fails—to make such reasoning work. (And think how different the world would be if everyone were such a failure!) He knows he has become a mutant: "Everybody is looking like one kind of animal, no more human." He knows he is a force of terror: "Person is running away from us like we are sickness, like we are the most evil thing to be on this earth." He knows his actions blaspheme nature; thus he wants to ask the sun "why it is even thinking to shine on this world." The very insistence of his mantra, in which he repeatedly denies his "badness," is proof of its inadequacy: "It is never working," Agu admits, "because I am always feeling like bad boy." Coercion might mitigate guilt, but it does not equal innocence: Nothing can undo the ugliness he has brought into the world.

Agu is a sort of child savant who intuitively knows that solidarity with others—based, first and last, on the recognition that they suffer as we do—is our only hope of remaining human. (This is the identical insight that informs the work of Levi, who wrote that an Auschwitz inmate reentered humanity at the very moment he offered another a piece of bread.) That Agu cannot act on his knowledge—that he is forced to act against his knowledge—makes Iweala's book a tragedy. But I am not sure it is the right kind of tragedy, which is to say that the firmness of Agu's moral compass may offer us false comfort; isn't it just as likely that systemically brutalized children can never reclaim themselves? Iweala's strength as a novelist is to create an interior world for Agu that is vivid, believable, and terribly moving, but it may be a romanticization all the same.

* * *

The grown men—convicted killers in the Rwandan genocide—whom Jean Hatzfeld interviewed for Machete Season: The Killers in Rwanda Speak are no Agus. They do not consider themselves animals or see any reason for the sun not to shine; on the contrary, they hope to simply resume normal life, and at times they seem not to quite understand what all the fuss over the genocide is about. A vast emptiness dwells in these men in exactly the places that reason, empathy, and remorse should occupy. Because of this, Machete Season is one of the most bewildering, despair-inducing books I have ever read; perhaps not since Eichmann have mass murderers appeared so unexceptional, and therefore so terrifying. The killers' chilling obliviousness to the nature and the meaning of their crimes—to themselves—inspires a kind of negative awe.

Hatzfeld is the son of French-Jewish parents who became refugees from Hitler. He joined the leftist French newspaper Libération in the 1970s; since then he has reported from numerous countries, including ones in Africa and the Mideast, and he covered the war in Bosnia. Six years ago, he published Into the Quick of Life, a book on Tutsi survivors of the Rwandan genocide; Machete Season is his follow-up, albeit a reluctant one. "Throughout this work with the survivors, I did not contact the killers," Hatzfeld writes. "The idea never occurred to me. . . . The killers meant nothing to me." He undertook the second book only in response to entreaties from readers.

The ten Hutu men Hatzfeld interviewed were in jail at the time (one had received the death penalty): "Only an imprisoned killer . . . can or will tell his story," Hatzfeld notes. They had grown up together in the hills surrounding Nyamata as a "close-knit gang of pals," and they did their killing together, too. Eight were farmers, one a teacher, another a civil servant; only three belonged to a political organization; at least one had a Tutsi wife; all attended church, some more than others. Nothing about them suggested that they would become sociopaths. "These men had seemed destined for nothing beyond choosing a wife to share a rural existence on a hill in a little country in the heart of Africa, a life lived in uneasy tolerance of their neighbors, without television or any influx of immigration to connect them to the vast outside world," Hatzfeld observes. "From one day to the next, they let themselves be swept up in a whirlwind of phenomenal carnage."

A continual shock of this book is the perverse meanings that ordinary, even pleasant words take on. "Helping out"—as in, "I was helping out at the church"—sounds nice, but here it means assisting in mass killings. A man describes his multiple—uncountable—murders as a "stimulating . . . diversion." A "recreational break" refers to torture, also described as "a distraction" to break up "a long work day." The air of calm reasonableness with which the génocidaires proffer their recollections jolts the reader again and again. Here is genocide as a form of self-development: "Each person was allowed to learn in his own way, according to his character," Pio explains. "You killed the way . . . you felt it, each at his own speed."

For these men—and, we can infer, hundreds of thousands of their Hutu compatriots—the spring of 1994 was the best of times. "I left [my house] every morning free and easy, in a hurry to get going," recalls Léopord. "I saw that . . . the results were good for me, that's all. . . . I want to make clear that from the first gentleman I killed to the last, I was not sorry about a single one." Alphonse recalls, "Us, we felt carefree and contented," while Élie remembers, "That time . . . showed us a welcoming smile." The men repeatedly refer to killing as "work," and it is clear that this was the most unalienated labor of their lives: "We can't say we missed the fields," Pio says. "Killing was a demanding but more gratifying activity." These words—free, easy, contented, gratifying—are not used ironically, or subversively, or to signal their dialectical opposites. No, the words mean here exactly what they mean elsewhere. There's no getting around it: Murder was fun.

Like Nazi Germany, Rwanda's Hutu Power regime offered a kind of populist paradise to the fortunate majority. For them, the genocide was an exercise in brotherhood, though of a horribly twisted kind, and they remind us of how solidarity within a self-defined group can be utterly severed from compassion for those outside it. Men who were most skilled in violence—the state-affiliated interahamwe militias—would, Pancrace says, "lend a hand" to the novices, offering "advice on what paths to take and which blows to use." Mutual aid took on a whole new meaning: "Someone who couldn't get used to polishing off his victim could just walk on or ask for help," Jean-Baptiste says. "He would find a supportive comrade behind him." And while the extent of coercion in the genocide is still debated, the killers of Hatzfeld's book did not—unlike Agu—operate for the most part under threat of death: "Discipline was relaxed because it wasn't necessary anymore," Jean-Baptiste continues. "I don't know anyone who was struck because he refused to kill." But the men say that fines were levied on the recalcitrant.

"Difference" feminists should take pause at this book. Though Nyamata's women did not partake in the actual killings, they seemed fully aware of what their husbands were doing and, among other things, rewarded them sexually for it. "With my wife, things went normally," Élie remembers. "She knew that after such a day I could not do without it." Women were among the most rabid looters of the dead Tutsis, stripping their houses of implements and their bodies of bloody clothes. (Among the perpetrators, the genocide is fondly remembered as a time of plenty.) Most of all, according to Hatzfeld, there is no known case of any Hutu woman in Nyamata actively opposing the gang rapes that accompanied the genocide or, according to one survivor, of protecting a Tutsi child.

This is especially odd given the longstanding web of relations between the hunters and their prey; it's likely that in no other twentieth-century genocide—of the Armenians, of the Jews, of the Cambodians—did killers and victims know each other so well. In Rwanda, people murdered not only their neighbors, friends, and workmates but sometimes their own spouses, parents, and children. Yet Hatzfeld notes the alarming lack of outright resistance or, even, instances of simple compassion. "People who have lived through a war often tell wonderful stories about friendships, incredible romances, amazing gestures of solidarity," he writes, and this was true "in Vietnam, Ireland, Lebanon, Angola, El Salvador, Israel, Chechnya." Rwanda was different. "In Nyamata, however, we find not one comradely impulse among teammates, not one gesture of compassion for helpless babies. . . . No bond of friendship or love that survived from a church choir or an agricultural cooperative. No civil disobedience. . . not a single escape network, although it would have been easy . . . no convoy . . . no web of hiding places." Hatzfeld regards this lacuna as a special characteristic of genocide, though I am not so sure; even Yad Vashem, Israel's Holocaust institute, has found over twenty thousand "righteous Gentiles" to honor (albeit only four hundred from Germany itself).

In her brief preface to Machete Season, Susan Sontag writes that "the issue" the book raises is "not judgment" but "understanding." Yet listening to these impassive killers makes comprehension more rather than less difficult. Indeed, it calls into question the whole notion of comprehension; I am not sure what it means to "understand" Alphonse when he says, "The babies . . . were whacked against walls and trees or they were cut right away. But they were killed more quickly, because . . . their suffering was of no use. . . . The babies could not understand the why of the suffering, [so] it was not worth lingering over them." The more the men talk, the less they explain; the more reasonable their tone, the more evident their madness.

To fail to understand the deliberate, sober cruelties that flood Machete Season is not to separate the genocide from human history or to enter a realm of obfuscation, religious mystification, or helplessness. It is simply to acknowledge that human beings do things that human reason cannot comprehend. Surely Rwanda—surely any genocide—qualifies as one of those events in which, as Hannah Arendt wrote, there is a "grotesque disparity" between action and rationale. Survivors—who experienced the violence as anything but banal—are clearest on this; in Hatzfeld's previous book, they continually express a sorrow-drenched bewilderment about the reasons for their suffering. Of course they know the theories of the genocide: of Hutu-Tutsi rivalry, of scarcity of land, of Hutu fear of takeover by the Rwandan Patriotic Front. But none of this quite explains why one day in the late twentieth century their neighbors, friends, workmates, and relatives turned on them with pitiless ferocity; none of it explains the lust to humiliate, the pride of the killers, the amputations, the sexual tortures, the infanticides, the disembowelments, the incinerations. These were not just deaths, and not just mass deaths, but hideously painful, happily executed deaths. As a survivor named Sylvie Umubyeyi tells Hatzfeld, "When I think about the genocide, in moments of calm, I mull over where to put it properly away in life, but I find no place. I simply mean to say, it is no longer anything human." Who can tell her that she is wrong? Who has found the proper place for all this?

* * *

In the wake of the Iraq invasion, many have predicted that the US has lost the authority to intervene abroad. In the New York Times Magazine, David Rieff wrote, "Should a humanitarian or a human rights justification always trump other concerns? What if the state doing the intervening has little or no credibility in the region, as the polls suggest is now true of the US in the Middle East?" These questions are not wrong to pose, except that they are not really posed as questions. Reflexive isolationism as a response to the very real failures in Iraq would be not only mistaken but potentially criminal. The West—the United States and United Nations—did not try to stop the slaughter in Rwanda (or, for the longest time, in Liberia or Sierra Leone); and it is worth noting the response of the génocidaires to such benign neglect. Originally, they thought, the UN troops already stationed in Rwanda would prevent the genocide. But things turned out otherwise, and the killers were surprised by their good luck. As Adalbert recalls, "We witnessed that flight of the [UN's] armored cars along the road with our own eyes. Our ears no longer heard murmurs of reproach. For the first time ever, we did not feel we were under the frowning supervision of whites. Other encouragements followed that assured us of unchecked freedom to complete the task. So we thought, Good, it's true, the blue helmets did nothing. . . . We were certain of killing everyone without drawing evil looks." (A Tutsi survivor put the same thought differently: "God himself showed that he had forgotten us, the whites even more so.")

One could argue that the Rwandan genocide was special, peculiar, unprecedented. And it was. Yet this could be said of many political events; as Arendt observed, every act that tries to change the future—and genocide is that—introduces us to something new. Though not, of course, to something we would necessarily wish to know, or that we can claim to have mastered.

Susie Linfield, the associate director of the Cultural Reporting and Criticism program at NYU, writes about politics and culture.