The Korengal Valley in eastern Afghanistan is harsh in nature and war, a bitter and beautiful landscape that bonded a small band of soldiers whose efforts epitomized America's limitations against the antipathy and resilience of an enemy it could neither fathom nor tame.

The burden and euphoria of battle are stamped on the men in "Korengal," Sebastian Junger's new documentary on an outpost where 42 Americans were killed in their country's longest war. The film, a sequel to his 2011 Academy Award-nominated "Restrepo," rattles with camaraderie and bravado but is acutely reflective of the trauma and hidden scars soldiers endure when the adrenaline of a firefight subsides and quiet falls across the hinterlands.

"I started thinking that God hates me," said Army Sgt. Brendan O'Byrne, who has a shaved head and a reddish beard and sits in a dark room recounting his ordeal and finding little solace. "I'm not religious or anything, but I felt like there was this hate for me 'cause I did sins.... That's the terrible thing of war. You do terrible things and you have to live with them afterwards but you'd do them the same way if you had to go back. So what do you do? It's an evil, evil, evil thing inside your body. It's like … good versus evil inside there."

"Korengal" moves beyond the sustained combat of "Restrepo" to reveal, said Junger, the emotional experiences of battle: "fear, killing and love." The film peels away war's romanticism and explores the psychological consequences of sustained conflict on mind, body and soul. "I was trying to unpack that experience," he said, "to understand how complicated and damaging and compelling combat is."

The Korengal Valley is a visceral symbol in the 13-year-old war. After hundreds of billions of dollars spent in Afghanistan and more than 2,300 American lives lost, the Taliban are weakened but not defeated, corruption reigns in villages and cities, and the once Western-friendly President Hamid Karzai has turned against Washington. U.S. involvement in that battered country — as in Iraq — has been outlasted by extremists who sweep across stunning mountain passes and refuse to wither against the most powerful military in the world.

Filmed in 2007-08, "Korengal," which opens in Los Angeles on June 13, arrives like an eerie postcard from a strange, bygone trip. President Obama recently announced that U.S. forces will withdraw from Afghanistan in 2016, ending a conflict that began as a hunt for Osama bin Laden in the surreal weeks after 9/11. Obama's new defense strategy relies more on technology, proxies, sanctions and drones than on prolonged deployments of American soldiers.

The troops in the Korengal Valley's 173rd Airborne Brigade are ragged reminders of the imprints of war and the price of moving on. A few feature films such as "The Hurt Locker" and "The Messenger" have told poignant stories of tormented soldiers, and there have been a few insightful documentaries that hunker with troops on the front lines.

Another new documentary, "The Hornet's Nest," is based on footage shot by ABC war correspondent Mike Boettcher and his son, Carlos, embedded with U.S. forces. But in general the grinding conflict has turned to faint noise on an American political and cultural landscape attuned to financial crises and Marvel Comics superheroes.

Author of "The Perfect Storm" and "War," Junger lived for months with the men, many with the echo of boyhood upon them, surviving drudgery, grit, split-second volatility, boredom and doubt. War is sound and fury broken by moments of unnerving stillness, or as one soldier put it, "You go from 100 miles per hour into a dead hole."

They are unified in duty and at times misguided in mission; they try in vain to win over villagers and share a deep honor and intimacy that wives and children, mothers and fathers, cannot know or penetrate.

"Pretty much every day we got in a firefight," said Army Spc. Misha Pemble-Belkin, who hails from Oregon and wears dog tags and a knit cap. "Every single day someone was trying to kill us. Our friends were getting shot next to us. People lost arms, lost legs. We had our friends get killed, and you're thinking in your head I still have another 10 … months to go.... I never thought I was going to make it out of the valley alive."

Pemble-Belkin and his fellow soldiers in Afghanistan and Iraq were stitched into sharp debates between conservatives and liberals over U.S. foreign policy. But neither side fully grasped the wider dimensions of those conflicts or the motivations and demons of the warriors who fought them.

"The right wing imagines soldiers are good patriots just doing their duty, and they [conservatives] don't want to engage with the very real moral cost of violence," said Junger, whose cameraman on both documentaries, Tim Hetherington, was killed in Libya in 2011. "The left wing does not want to engage with the idea that the guys they're seeing in this film enthusiastically joined the Army and really enjoyed the hell out of combat and really miss it."

The cost of military intervention is riven with passions, including the debate last week over the wisdom of the Obama administration releasing five Taliban commanders from Guantanamo Bay prison in exchange for U.S. Sgt. Bowe Bergdahl, who was a prisoner for nearly five years. That episode was the latest twist in a war of suicide bombings, beheadings, massacres and the estimated deaths of between 15,000 to 20,000 civilians since 2007, when the United Nations began keeping statistics.

"The sheer pain of it makes it something filmmakers and audiences want to turn away from. The overall picture is one that invites despair," said Robert Greenwald, president and founder of Brave New Films, which in 2009 produced the documentary "Rethink Afghanistan." "Afghanistan was and is an awful and painful tragedy. Lives were lost and billions of dollars spent. I defy anyone who says it was a good idea."

In 2010, the U.S. withdrew from the Korengal Valley outpost, which was strategically used to disrupt Taliban weapons smuggling routes and to draw insurgent fire away from towns and villages U.S. forces were trying to rebuild near the Pakistan border. The soldiers stationed there encountered roadside bombs and slipped in and out of the lives of villagers trapped between the U.S. and the Taliban.

"They're a bunch of liars," Capt. Dan Kearney, who lost a soldier in action on his first day in charge, said of the locals, some of whom would accept American medical supplies one day and shoot at U.S. soldiers the next. "They didn't want us. They didn't want our help."

The troops in the Korengal Valley were bonded by a "very ancient, intensely human experience," but Junger said they came home to a nation that was fragmented and alienating. "Western society for all its wonderful arts and sciences and everything else has generated that highest levels of suicide and depression and child abuse and mass killings — within our own communities — in human history. They're going from an experience of extreme closeness … and suddenly they're sleeping in an air-conditioned room by themselves in an American suburb."

The soldiers, like Afghanistan, carry the stains of war toward some unknown destiny. About 60% of eligible Afghans voted in the first round of presidential elections in April, and more are expected for the final vote on June 14. The Taliban, fearful of losing legitimacy, have stepped up attacks on government targets. Many U.S. soldiers have since returned home, taking antidepressants, waking in the night and trying to fit in amid the perplexed faces of families and friends.

"Everyone tells you you did an honorable thing," said Sgt. O'Byrne. "You did what you had to do. I just hate that comment, 'Did what you had to do,' 'cause I didn't have to do any of it. And that's what the thing is, the hardest thing to deal with, you know, I didn't have to do.... I didn't have to go into the Army. I didn't have to become Airborne infantry.... 'You did what you had to do' just drives me insane. Is that what God's gonna say, 'You did what you had to do, good job,' punch you on the shoulder and say welcome to heaven? I don't think so."

