The first one I ever saw was in a hayfield above a town called Suha Reka. It was right after NATO had finished bombing Serb forces in Kosovo in 1999, and I was driving through the ruined towns writing about the war crimes that had triggered the bombardment. It was a young girl who had been dead for a while, so we could smell her long before we got there. Locals said she was 16 and had been taken up there by a dozen or so Serb militiamen who had gang raped her and then cut her throat. She was mostly gristle and bone when we saw her, lying in the sun with her legs spread and a grimace on her face. The only way to tell she was female was the red nail polish on her fingers and toes.

The only morally defensible film about war, it would seem, is one that condemns it; everything else is propaganda.

The trailer for Sebastian Junger and Tim Hetherington's Sundance Award-winning documentary, Restrepo.

I had no reaction at all until I got on the plane two weeks later and suddenly started sobbing. Back home, I found myself getting into arguments with my friends who had been violently opposed to the NATO intervention, and I just kept thinking about that girl and getting more and more angry. Several times I had to leave the room in order to preserve my friendships with those people. I couldn’t understand why my friends were less troubled by the dead girl than by the NATO bombing that had stopped such things. I had come of age after Vietnam, when the United States was involved in a series of covert actions all over Central and South America, and those actions resulted in the deaths of hundreds of thousands of civilians. Back then, the very definition of being left wing was to be outraged by that repression and violence. This new era of liberal passivity in the face of civilian suffering made no sense to me.

The horrors of Latin America were the product of Cold War paranoia, but after the fall of the Berlin Wall others took their place. In 1995, Bosnian Serb forces rounded up 8,000 men and boys from the city of Srebrenica and machine-gunned them into pits, then used bulldozers to bury them. It was the last straw in a war that had claimed a quarter million civilian lives, and it helped trigger a three-week NATO bombing campaign that quickly shut down the war. Back home, the right wing was upset because we were risking our soldiers’ lives—though not one died during the intervention—and many on the left were upset simply because the U.S. Air Force was once again dropping bombs on people. Neither side seemed much concerned with the Bosnians themselves.

More and more, the focus of my journalism was to document and broadcast the suffering of civilians in war. Everyone agrees that war is bad, but that doesn’t mean it won’t happen, and the world’s most powerful nations are unavoidably left wondering whether they should intervene when it does. After Kosovo, I went to Sierra Leone, where tens of thousands of civilians had been killed or maimed by the Revolutionary United Front in what was essentially a war for diamonds. After three years of carnage, a single unit of British paratroopers stopped the war in its tracks. Only one British soldier was killed. A couple of years later, I found myself in Liberia during a rebel offensive that managed to drop mortars into a crowd of refugees in a U.S. Embassy annex in Monrovia. An American warship waited offshore, doing nothing, and in protest the locals piled the bodies of dead civilians in front of the embassy gate. I had never seen a pile of bodies before, and the only thing I could think to do was count them. There were 27, as I recall, though I think several children were hidden under the bodies of adults. I was the only foreigner in a mob of angry and traumatized locals, and I finally left when people began demanding why the U.S. wasn’t sending troops to stop the slaughter. A few weeks later, the Marines came ashore and ended the war not only without a single casualty but without firing a single shot.

When I got back to New York, I was surprised to see a young white man on the subway reading a radical newspaper that sported the puzzling headline, “U.S. OUT OF LIBERIA!” The moral outrage at any use of the U.S. military now seemed to outweigh the moral outrage at actual civilian suffering—a complete inversion of the liberal principles I’d grown up with. The culmination of this paradox came in Afghanistan after Barack Obama took office and attempted to correct the amazingly short-sighted policy of the Bush administration.

I had been going to Afghanistan since 1996, when Taliban forces swept through the country and began imposing their ideological cruelties on the Afghan people. I went back in 2000 and then again in 2001, walking into Kabul with the Northern Alliance as people greeted them with dancing and laughter and music in the streets. I remember an Afghan man running up and hugging me when he found out I was American; in his eyes, America had saved him from the tyranny of the Taliban. Not one American soldier had died at this point. It was a hard opportunity to blow, but we managed to. The Bush administration left 19,000 American troops in Afghanistan and shifted their focus to Iraq.

I will leave that debate to others; personally I was utterly against the invasion of Iraq, but I’ve never been there and can’t claim any direct knowledge. Afghanistan was my concern, and as the situation deteriorated, I went back again and again. In the spring of 2007, I began a yearlong project of following one platoon of American soldiers—about 35 men—at a remote outpost in the Korengal Valley, the eastern part of the country. The outpost was named Restrepo, after the platoon medic who was killed early in the deployment, and while I was there, nearly one-fifth of the combat in all of Afghanistan was happening around our little base. I wrote a book about it, called War, and shot and directed a film—called Restrepo—with British photographer Tim Hetherington. As longtime war reporters, Tim and I were both well-acclimated to the idea that journalists refrain from advocating any particular political position or course of action, and that was the approach I took with both the book and the movie. “We don’t tell people how to think,” was how Tim put it.

We shot 150 hours of video and then interviewed eight of the soldiers after they had returned to their base in Vicenza, Italy. Neither the film nor the book ever reach for a wider truth or try to evaluate the political dimensions of the war. It was purely a soldiers'-eye view of combat: They can’t ask a general or a diplomat why they’re fighting, so neither would we. Our job, as we saw it, is to document the effects of war on people, and in this case the people in question were American soldiers. On later assignments we could return to our work among the civilian population in the country.

Restrepo won the grand jury prize at the Sundance Film Festival and went on to enjoy commercial distribution in cinemas around the country. For a while, it was the top-grossing independent film in the country, and support seemed to come from across the political spectrum. Conservative reporters seemed to love it because a pair of “left-wing” reporters had refrained from morally deconstructing the war. And liberal reporters—swayed by the same raw footage of American combat deaths and civilian casualties—saw it as an irrefutable indictment of war. They decided that Tim and I had secretly made an antiwar film but just hadn’t told anyone. Tim and I watched this debate without saying a word. We have opinions, of course, but we suspected they were far more complex than either political camp wanted to hear.

It took about a month, but the criticisms finally started to trickle in. Some reviewers argued that to have no agenda in a film about war amounts to an acceptance of the status quo—which is essentially a pro-war position. The only morally defensible film about war, it would seem, is one that condemns it; everything else is propaganda. I understand their logic, but the critics put themselves in a very awkward position. The age-old objection to war is that it kills people, and over the past hundred years, wars have killed more and more civilians and fewer and fewer of the actual combatants. An implacably humanistic approach to war—to all misfortune—would be one that chooses the path of lowest civilian casualties and pursues it unwaveringly. Anything else places strategic or ideological interests above the welfare of human beings.

Society makes that choice all the time: Police officers carry guns and occasionally kill innocent people, but they save many more from random violence and crime. (Why is it, by the way, that pacifists never object to having an armed police force?) Inoculations kill a few people but protect far more from deadly diseases. Allied forces during World War Two killed tens of thousands of French civilians during their bombing campaigns, but that paved the way for the defeat of Germany. The net cost to humanity was probably lower than if the Nazis been able to do whatever they wanted with the world. History is filled with agonizing decisions that protect most people while sacrificing a few. It’s not fair to those who die, but the alternative is to have even more people die. Which brings us to Afghanistan.

During the 1980s, the Soviet Union waged a war in that country that killed as many as 1 million Afghans and drove one-fifth of the population—roughly 6 million people—into neighboring countries. After the Soviets withdrew, Afghanistan imploded in a brutal civil war that killed an estimated 400,000 civilians. According to Human Rights Watch, 5,000 civilians were killed in Kabul during the first few weeks of 1993 alone. The violence diminished somewhat when the Taliban took control, but that came at the cost of unspeakable repression—particularly of women and non-Pashtun groups. That era was brought to an end by NATO military action in 2001, which toppled the Taliban from power and installed a corrupt and self-serving government in its place.

Whatever its flaws, the current situation represents the lowest level of violence in Afghanistan since 1980. Estimates of civilian deaths in the nine years since NATO began operations range from 12,000 to 30,000—a tiny fraction of what they were during the previous decade. ( According to the United Nations, more than two-thirds of the civilian deaths in 2009 were caused by the Taliban.) Conversely, infant mortality has gone down by roughly 20 percent and over 6 million children are now receiving an education—the highest number in Afghan history. Many of those children, of course, are girls.

The war, however, is going worse and worse. I don’t have a son or daughter over there, I don’t have anything personal at stake in this miserable affair, so I feel completely unworthy to answer the question of whether the United States should keep fighting or pull out. As a journalist, the only thing I can do is try to guess the likely consequences of each choice and explain them to people who can’t go over there to see for themselves. If NATO remains in Afghanistan, it can probably maintain the current level of stability and prevent Taliban and al Qaeda forces from reestablishing a base in that country. If NATO withdraws, those forces will almost certainly sweep into Kabul and precipitate another protracted civil war. That risks recreating the circumstances that led to the 9/11 attacks, but the human and economic costs of another attack might possibly be lower than if we continued waging war.

What is almost certain, however, is that in Afghanistan, every index of human misery will probably skyrocket back to pre-9/11 levels. We are a great and powerful nation, and I am not suggesting we owe it to the Afghans to protect them from themselves. But for the sake of intellectual honesty, don’t imagine NATO should withdraw for their sake. The Afghans will undoubtedly be the ones who pay the heaviest price for a NATO withdrawal. That’s not necessarily our problem, but don’t delude yourself into thinking it isn’t so.

Have you seen Restrepo? Do you feel it is “apolitical”? Is war ever necessary? Tell us your opinions on the Restrepo Facebook.

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Sebastian Junger a contributing editor at Vanity Fair, and the author of WAR, a New York Times bestseller published by Twelve. He is also the co-director, with photojournalist Tim Hetherington, of the documentary film Restrepo , winner of the Grand Jury Prize for Documentary at Sundance.