Like many American kids, Chuck Newton went to war to kill.

It was after the September 11, 2001, terrorist attacks and he was burning for revenge. “I want to go fight,” the 17-year-old told his parents. Understandably, they said “no.” When he was old enough to enlist without their permission, off he went to Marine boot camp at Parris Island and then to two combat tours in Afghanistan with Charlie Company, 1st Battalion, 6th Marine Regiment.

By the time he returned home, he had killed many times, with different weapons and under different circumstances. In our conversations, he seemed awash in conflicting emotions of pride, remorse, bitterness and defiance. In combat, he said one day, there are things you know you shouldn’t do but everybody does them.

Newton is a tall, rangy guy from Brooklyn with a fine ironic sense of humor. His dark hair, shaved down below stubble in Afghanistan, is now almost shoulder-length. He was skeptical at first about talking to me. But as a correspondent in Afghanistan, I’d been under fire with his battalion, and eventually he agreed to trust me with some of his reflections on war and killing.

Rather than confront the morality of killing, we’ve surrounded it with a conspiracy of silence.

He is careful and deliberate, gathering his thoughts before he speaks, as if his words are precious and not to be wasted or misunderstood. He lets them out a sentence or two at a time and checks your eyes to make sure you’ve got it.

“I wanted to kill people ― badly. In the same way you wanted the people responsible for the [9/11] massacres to get killed. And I went and did it. And thinking back on it, you know … that’s too heavy for one person to take on. I don’t know that there’s anybody who’s not psychopathic who isn’t hurt by it.”

That’s the profound and unpleasant truth, and I suspect each us knows it. Under any circumstance, justified or not, killing another human exacts a moral cost. We send men and women into war knowing that they will collide with a moral dilemma no one can resolve: To be effective warriors, they must participate directly or indirectly in killing, but killing violates one of our oldest taboos.

Rather than confront the morality of killing, we’ve surrounded it with a conspiracy of silence. Official Defense Department war dispatches speak of “kinetic events” and list targets destroyed in airstrikes, while the word “killed” rarely makes an appearance. The father of a new military enlistee doesn’t say with pride that “my daughter has signed up to kill.” Military recruiters studiously avoid the word.

Many of the new soldiers I’ve talked with say they never thought about the moral consequences of killing. The Rifleman’s Creed memorized by all young Marines demands not that they kill, only that they must fire a weapon “true,” and adds, “We will hit.”

Alaa Al-Marjani/Reuters U.S. Army troops on duty at Qayyara, south of Mosul, Iraq.

Asking a combat veteran if he or she ever killed someone is considered rude, and for the veteran, it’s a cause for excruciating discomfort. Most likely, the answer lies tightly wrapped in layers of pride and guilt and confusion, an experience hard earned and not lightly shared.

In his blog, Thoughts of a Soldier-Ethicist, Army Lt. Col. Peter Kilner, who teaches philosophy and military science at the U.S. Military Academy at West Point, acknowledges the point when he writes, “We don’t tell our family members and civilian friends that we killed in war. If they ask, we answer matter of factly and move on. When acquaintances and strangers ask if we killed anyone in war, we lie or ignore them; they have no right to know.”

Kilner adds, “Those who haven’t experienced combat couldn’t possibly understand what it means to kill another human being, and we want to be looked at for the purpose we achieved (protecting them) not for the means we used (killing others).”

No wonder so many veterans often feel misunderstood after returning to civilian society. No wonder so many come home and never talk about their wartime experiences. No wonder civilians are often reluctant to ask or say anything beyond a sincere but awkward “Thank you for your service.”

People used to deal with this openly. Many ancient societies believed that killing in combat, even under legal and morally justifiable conditions, defiled the warrior. That’s a constant theme in Greek tragedy. In the Old Testament’s Book of Numbers, Moses directed anyone who had killed in battle to remain out of camp for seven days of purification. In the seventh century, by order of the archbishop of Canterbury, warriors who killed in battle underwent 40 days of penance and banishment from the church. After the Battle of Hastings in 1066, a gathering of bishops ruled that “anyone who knows he killed a man in the great battle must do penance for one year for each man he killed.”

We’ve abandoned the practice of penance for wartime killing. But along with it, we’ve lost the principle of reckoning with the moral cost of battle. We send young Americans into war but no longer acknowledge what they do on our behalf. We no longer see a need, as our ancestors did, for cleansing and acceptance.

The enduring silence of our veterans and our own denial of war’s realities speak volumes about the need for healing. We might start that long-overdue process by acknowledging openly that war imposes moral costs on our warriors. Then we must begin to talk to each other.

Until then, Veterans Day will be an unfulfilled promise.

David Wood is The Huffington Post’s Pulitzer Prize-winning senior military correspondent. His book, What Have We Done: The Moral Injury of Our Longest Wars, was published Nov. 1 by Little Brown.