Men like Delaware County native Shannon Meehan.
In June 2007, Meehan was an Army lieutenant leading a major house-clearing operation in Baquba, north of Baghdad.
The mission was going well, Meehan told me during a phone conversation this week. At one point, he and his comrades approached a house they feared to be booby-trapped. Thinking it could be an enemy safe house and not wanting to send his men into a potentially dangerous situation, Meehan ordered an artillery strike to destroy the building.
Soon after the mortar round left the building in ruins, an adjacent platoon delivered the gut-wrenching news.
The house contained no enemy fighters.
But killed in the strike were an innocent mother, father and their children. "Of course, it's a day I'll never forget," Meehan says now. "It's the day I called down a silence on a family that will live forever on in me."
He was shaken, but managed to complete the mission. In September 2007, an IED explosion left Meehan with a traumatic brain injury and serious damage to his back.
The Upper Darby native and former wrestling star returned home a decorated hero. He brought with him a Bronze Star, Purple Heart and an Army Commendation for Valor. And post traumatic stress disorder.
Meehan has written and spoken extensively about what happened in Baquba. His book, "Beyond Duty," came out last year.
In an op-ed for the New York Times in February, he wrote that the "feelings of disbelief that initially filled me quickly transformed into feelings of rage and self-loathing." He couldn't shake the image of the dead family. In the process, he said he lost any regard for his own life.
Even the birth of Meehan's son, Brady, in January was a tempered blessing. "I'm sure every mother or father have a certain amount of anxiety going into their first child. But for me it just felt so heavy, this decision," he told me. "I just had such guilt out of knowing what I had done . . . I'm bringing this gift into this world, and it's the same type of gift that I had destroyed before, the same type . . . that I had robbed someone else of."
In a way, Meehan's story reveals the costs of modern combat we don't often tabulate.
War is hell. Unfortunately, part of that hell is the reality of civilian deaths. And our hearts break for those caught in the cross-fire.
But what about the American soldier who unwittingly plays a role in that tragedy? As Meehan's experience proves, no amount of military training or exposure to the anguish of battle makes a soldier immune to the aftereffects of killing. The dark thoughts stick in the minds of even America's most distinguished post-9/11 heroes.
I'm thinking, too, of those operating the escalating number of Predator drone missions in Iraq, Afghanistan and Pakistan.
These soldiers are playing a sophisticated video game in a trailer 8,000 miles from their target. But they still face the most nuanced of decisions. Pull the trigger? Fire the missile? Kill the bad guy, but risk ending the life of someone simply in the wrong place at the wrong time?
Just because these service members return home after work, unlike those on the ground in the Middle East, doesn't mean they leave the guilt or anger at their desks.
"What's lost in all of that is the people that were actually involved in it - the family that was killed or the soldiers that were responsible that now have to live with this," Meehan said. "You don't hear that story. The best I can do is to help make the space for that discussion."
And the rest of us need to do all we can to look after those Americans who have a lifetime to replay and recast decisions they made on the battlefield.
Listen to Michael Smerconish weekdays 5-9 a.m. on the Big Talker, 1210/AM. Read him Sundays in the Inquirer. Contact him via the Web at www.smerconish.com.