November 2004， against a shattered wall in south Fallujah in Iraq， with video rolling， I conduct a battlefield interview with US Marine Corporal William Wold. He has just shot six men dead inside a room adjoining a mosque and is juiced with a mix of adrenaline and relief.

“I was told to go the room，” he says，“and my first Marine went in… he saw a guy with an AK， I told him to shoot the guy， then I shot the six guys on the left… and my other Marine shot two other guys.”

Wold grew up near Vancouver in Washington State. A high-school linebacker， he had a college football scholarship waiting for him， but gave it up to join the Marines.

“My fiancées worried that Im not going to come back the same. Ill never tell her what things I did here. Ill never tell anybody， cause Im not proud of killing people. Im just proud to serve my country. I hate being here， but I love it at the same time.”

Wolds fiancée was right. He wouldnt come back the same. He thought his war was over， but a few months later， back in the safety of his childhood home， surrounded by his adoring family， the dark secrets and all the guilt emerged from his mind—like the Greeks from their hollow wooden horse， unrelenting in their destruction of ancient Troy.

A recent study by the US Department of Veterans Affairs （VA） shows that nearly two-dozen veterans are killing themselves every day， nearly one an hour. This attrition， connected at least in part to combat-related post-traumatic stress disorder （PTSD） and other war-related psychological injuries， is an enormous price to pay for avoiding the subject. So great， in fact， that the total number of US active duty suicides in 2012 （349） was higher than the number of combat-related deaths （295）.

“When a leader destroys the legitimacy of the armys moral order by betraying ‘whats right，” writes psychiatrist Jonathan Shay， an expert in combat trauma， in his book Achilles in Vietnam （1994）， “he inflicts manifold injuries on his men.”

This could be what happened to Corporal William Wold. Wolds mother Sandi said he was fine for a while when he first got home， but after a few months the darkness seeped out. He couldnt eat and he never slept.

The transgression that bothered him most wasnt the carnage in the mosque， but another， even more disturbing incident， an accidental killing at a vehicle checkpoint in Iraq. The vague description Sandi gave to a local television reporter is horrifying： “A vehicle came through that hadnt been cleared，” she said. “The lieutenant says：‘Take them out. He took them out. They went to the van—it was a bunch of little kids. And he had to take their bodies back to the family.”

Instead of killing an armed enemy， Wold had， through the orders of an officer， killed several children. The accidental killing of civilians in the Iraq War， as in all wars， is much more common than you can imagine. Numbers are so high it wouldnt benefit the military to keep accurate tabs； rigorous documentation would just fan the public relations nightmare and boost the propaganda value of those deaths for the other side.

Wold， like many combatants， was able to contain his guilt while still in Iraq. But when he returned home， he brought the Trojan horse with him. It was there， in the calm of these“safe” surroundings， that his guilt and shame overwhelmed him. He became addicted to the pain medication prescribed for an injury he had suffered in a roadside bomb attack and augmented that with methadone that he scored on the street.

One night a couple of friends came to visit Wold there. They went out together to see a movie and get tattoos. When they returned to his room， Wold couldnt remember if he had taken his medication or not—so he took it again， in front of his friends.

The next morning， the friends found Wold in bed， in the same position he had been when they had left him the night before. Only now he wasnt breathing. He was pronounced dead at 9：35am.

Sandi felt the Marines had failed her son. But she knew he had loved the camaraderie of the corps and had him buried in his dress blues. She also knew that the uniform was just the surface of a much more complex story， a story of belief， duty and honor yes， but also about how guilt over killing in the pursuit of those ideals could lead to ruin.

I met Lance Corporal James Sperry， like Wold， during the Battle of Fallujah in Iraq in 2004. I videotaped him after he had been wounded during the first day of fighting. Like Wold， Sperry came home with a head battered from war and filled with guilt. But Sperrys guilt wasnt over killing； it was over not being killed， survivors guilt. His unit suffered some of the highest casualty rates of the war.

He sent me an email six years after Fallujah， thanking me for helping carry his stretcher that day and asking if I had any photos of his comrades killed in action. “I was wondering if you had taken any photos of me during that time of injury and any of my fallen friends. I have lost 20 friends in this war and would like to get as many pictures as I can.”

That note came during a dark period of Sperrys life， when he was struggling with cognitive impairment and debilitating migraines from his physical injuries and a host of psychological issues consistent with moral injury. He met nearly all of its criteria， including purposelessness， alienation， drug and alcohol use， and even a near-suicide attempt （he went as far as to sling a rope over the rafters of his garage）.

His recovery， which took years， was not the result of a single act， but encouragement from family and friends， ongoing determination and a groundbreaking program from the Shepherd Center in Atlanta， which specializes in helping those with brain and spinal cord injuries.

Corporal Wold and Lance Corporal Sperry are just two of millions. According to US Department of Defense data， since 2001 about 2.5 million Americans went to war in Afghanistan and Iraq， with more than 800，000 deploying more than once. Nearly 700，000 of those veterans have already been awarded disability status， with another 100，000 pending， according to the VA.

They all need support. As Jonathan Shay wrote in Achilles in Vietnam： “When you put a gun in some kids hands and send him off to war， you incur an infinite debt to him for what he has done to his soul.”

2004年11月，在伊拉克的费卢杰南部，我靠着一堵千疮百孔的墙，在摄像机前对美国海军陆战队下士威廉·沃尔德进行了一次战地采访。他刚刚在一座清真寺旁的一间房间里射杀了6名男子，现在内心感到既激动又如释重负。

“我受命进入那个房间，”他说道，“我前面的那个队友进去了……看见有人拿着一把AK步枪，我让他开枪射杀那人，然后我就射左边的那六个……我另一名队友射杀了另外两个。”

沃尔德在华盛顿州毗邻温哥华的地区长大。高中时他是橄榄球队的线卫，本来获得了一所大学的橄榄球奖学金，但是他为加入海军陆战队放弃了奖学金。

“我的未婚妻担心我回去的时候就变了。我绝不会跟她说我在这儿所做的事。我绝不会告诉任何人。因为我不为杀人而自豪。我只为自己能为国效力而自豪。我讨厌待在这里，但同时又热爱置身其中。”

沃尔德的未婚妻是对的。他回去的时候就不再是原来那个人了。他以为他的战争结束了，但数月之后，当他回到安全的儿时家乡，回到挚爱的家人身旁，那深藏内心的阴暗秘密和愧疚便一涌而出——就如同希腊人从空心木马中涌出，毫不留情地将古特洛伊城摧毁一样。

美国退伍军人事务部最近的一项研究表明，每天有二十多名退休军人自杀，平均约一小时就有一名。造成这一损失的原因至少部分在于由战争引起的创伤后应激障碍和其他与战争相关的心理创伤，这是我们为逃避杀戮这一话题所付出的巨大代价。