American society is tremendously divided in its attitudes toward war. Most recently, the gap was visible in the 1992 elections, when Clinton’s anti-Vietnam activism meant entirely different things to his supporters and his opponents. One group—encompassing not just aging hippies and conscientious objectors but the left in general—regards all warfare as an atrocity and applauds opposition to it. The other, including soldiers as well as those who have never fought, sees war as an inevitability that only cowards evade. The very difficulty of the issue of wartime killing makes the gap almost unbridgeable, with each side clinging to its own brand of extremism. One may make heroes of killers, but the other abhors killing with the innocent absolutism of those who have never been forced into violence.

Lt. Col. Dave Grossman rides nobly into the mire with On Killing: The Psychological Cost of Learning to Kill in War and Society. A sociohistorical exercise in what he calls “killology,” his book is primarily an attempt to come to terms with the brutality of war without rejecting those who carry it out.

Grossman’s ideological bent is difficult to fix. He’s clearly been influenced by the movement of both liberals and conservatives against violence in the media: He contends, for instance, that recent atrocities are linked in part to “snuff films” and video games, and he eschews the euphemisms that military men use to understand their job. Yet he’s no dove—a soldier of 20 years, Grossman frequently refers to the necessity and dignity of war. He sums up his dilemma in the introduction to On Killing, explaining that though he has no wish to condemn those who kill in combat, he also respects those who refuse to take a life:

As a soldier who may have stood beside them I cannot help but be dismayed at their failure to support their cause, their nation, and their fellows; but as a human being who has understood some of the burden they have borne….I cannot help but be proud of them and the noble characteristic that they represent in our species.

For the first half of the book, Grossman deals primarily with this soldier who refuses to kill. This section—which requires only rudimentary knowledge of troop movements and battle strategy—will be of particular interest to antiwar activists who are not schooled in the finer points of military training. Grossman ranks with great new-school military historians like John Keegan and Paul Fussell in his ability to discuss war in terms that a general audience can understand. This comes in handy as he musters statistics from centuries of war to make a point that, however well-known it may be to generals, could astonish the lay reader: Soldiers throughout history have exhibited a near-total inability to kill their enemies.

In a discussion ranging from the conquests of Alexander the Great to Vietnam, Grossman uses bullet-to-kill ratios, anecdotes, and logic to prove compellingly that soldiers from all countries find it almost impossible to kill. In World War II, he contends, only 15 to 20 percent of American riflemen in combat would fire at the enemy at all; the rest loaded rifles, ran messages, or even pretended to aim and shoot. “The “firers’ seemed to accept this,” Grossman writes, and “the presence of the nonfirers seemed to enable the firers to keep going.”

By the Vietnam era, commanders had recognized this problem, and soldiers were receiving intensive training designed specifically to weaken their resistance to their task. But even then, more than 50,000 bullets were fired for every enemy soldier killed. The examples mount, proving Grossman’s point: Even with military training, humans find it extremely difficult to kill one of their own species—so difficult that “it will psychologically debilitate 98 percent of all who participate…for any length of time.”

Of course, the difficulty varies with a host of factors. If the killer is separated from his target by distance and technology—if he doesn’t look at a person at all, for example, but only at a blip on a radar screen—then it’s easier for him to abstract himself from what he’s doing. The Air Force discovered that less than 1 percent of the fighter pilots in World War II accounted for 30 to 40 percent of all enemy aircraft destroyed in the air. “When it came time to kill,” Grossman writes, “they looked into the cockpit at another man…one of the “brotherhood of the air’…and when faced with such a man…the vast majority simply could not kill him.” Conversely, gunners on Navy ships, who fired at specks on the horizon and in the sky, not only killed more efficiently but suffered fewer psychological consequences than pilots or foot soldiers.

The cause of most soldiers’ trauma is evident in accounts from the Vietnam War. Grossman repeatedly uses Vietnam to demonstrate that even in an intense atmosphere of xenophobia—which supposedly enabled soldiers to see the enemy as subhuman “gooks”—the instinctual prohibition against intraspecies killing held firm:

Michael Kathman, a tunnel rat crawling alone in a Vietcong tunnel…switched on the light and suddenly found “not more than 15 feet away…a (lone) Viet Cong eating a handful of rice….After a moment,’ Kathman recalled, “he put his pouch of rice on the floor of the tunnel beside him, turned his back to me and slowly started crawling away.’ Kathman, in turn, switched off his flashlight and slipped away in the other direction.

Such examples conclusively illustrate what Grossman calls the “burden of killing”; the next step is explaining how it’s borne. This section, a discussion of the ways humans are taught to kill, is rather more familiar to opponents of war. Antiwar activists have already pointed out the roles of xenophobia, group identification, and authority pressure in military life, and movies like Full Metal Jacket and Casualties of War have shown the public how recruits become killing machines. Similarly, Grossman’s report on Skinnerian conditioning comes as no surprise—it’s hardly shocking to find that the military uses human-shaped targets to make rifle practice more like the real thing.

Grossman doesn’t cast a positive light on such methods, but he doesn’t condemn them either. He offers no antidote to the chilling spectacle of soldiers being systematically stripped of their humanity—or, for that matter, to war killing in general. Rather than denounce the whole process, he instead emphasizes the differences between types of warfare. He rightly points out the moral distinction between soldier-to-soldier combat and the killing of civilians, straightforward attacks and atrocities.

This ambiguity is a courageous response to a complicated set of questions: For all their idealism, few peaceniks are willing to talk turkey like Grossman does. That makes his final answer to the problem of war all the more puzzling. He essentially proposes that all nations agree to limit war’s scope with codes of combat and restraints on the use of technology. “There is a precedent for limiting violence-enabling technology,” he notes optimistically. “After the tragic experience of using poisonous gases in World War I the world has generally rejected their use ever since. The atmospheric nuclear test ban treaty continues after almost three decades.”

Actually, recent history provides ample evidence that the consensus against such weapons is far from universal—witness the Aum Shinrikyo cult’s poison-gas attacks on Japanese commuters, or France’s nuclear testing, for example. But Grossman doesn’t allow the meagerness and flaws of his examples to dilute his positive outlook on modern warfare. If only all parties concerned can agree on the parameters, he concludes, then war can be conducted in a civilized manner.

Yet for all of Grossman’s hopefulness about the future of war, a sense of futility seeps through in his consideration of society at large. He makes the now-familiar contention that violence in the media desensitizes people, claiming that video games and action movies do to kids what drill sergeants do to soldiers. Grossman’s call to “resensitize America” is that of someone desperate to solve a problem that’s knottier than he’ll admit—this is not the regulated, motivated violence of wars, but the random violence of individuals. Though early on he quotes Bruno Bettelheim’s claim that humanity is fascinated with the “dark beauty of violence,” he backs away from any examination of how this fascination feeds, rather than is fed by, an increasingly brutal culture.

In this failure, Grossman is no different from war’s supporters and opponents, who cling to simplistic views of humans’ violent capacities. He’s at least capable of taking an objective, compassionate look at the struggles of the soldiers who do and don’t kill—even if his understanding falls short when he leaves the orderly ranks of the military.