Lt. Col. Joel B. Vowell kneels at the grave of Sgt. 1st Class Ofren Arrechaga in Hopkinsville, Ky., on Veterans Day. Vowell, 42, visited the veterans cemetery near Fort Campbell to remember two of his soldiers who were killed in Afghanistan. (Greg Jaffe/THE WASHINGTON POST)

Two visitors, their arrivals separated by a few hours, stop at a grave in Section 6, Row 5 of the Veterans Cemetery here. The burial grounds are cold and quiet.

A few miles away at Fort Campbell, thousands of soldiers are preparing for yet another tour in Afghanistan.

The first visitor arrives a little after 10 a.m. He is tall and lean, a 42-year-old Army officer. He wears a dark-blue dress uniform with four stripes on his right sleeve, each mark indicating six months spent in Afghanistan or Iraq.

Lt. Col. Joel B. Vowell commanded the soldier who lies in the grave. Sgt. 1st Class Ofren Arrechaga and five others died in an assault on an insurgent sanctuary in Afghanistan that Vowell planned and led a few weeks before his battalion came home. The deaths caused some soldiers and families to question whether the operation was necessary. The whispers stung Vowell deeply.

Among the angriest was Arrechaga’s 23-year-old widow, Seana. As Vowell kneels at the grave on Veterans Day, he can see a photograph of the couple clasping hands at their wedding. The photo is tucked behind a drawing of a ghost and a small sign that says “Spooky,” decorations Seana has placed for Halloween.

The relationship between Vowell and Seana, at once distant and uncomfortably intimate, reflects an important change in the American military. In past wars, soldiers were mostly unmarried draftees who ­deployed to combat zones as in­dividuals. Commanders often barely knew their men.

Today, troops fight as units, living and training together for years on gated Army bases far from the country’s big cities. Retired Lt. Gen. David Barno, a former top commander in Afghanistan, calls the practice “exclusionary bonding.”

The close bonds, sealed by the military’s growing sense that it is fighting a war that America has forgotten, have helped the Army withstand the strain of a decade of combat. One of the service’s biggest successes is that it has not been torn apart by the widespread discipline problems, racial tension and drug abuse of the Vietnam War era.

For those in tightknit military communities, the combination of proximity and isolation can produce intense emotion, especially in the wake of a soldier’s death.

Seana arrives at the cemetery a little after 2 p.m., accompanied by the couple’s 3-year-old son, Alston. Her shoulder-length blond hair matches the color of the straw scattered atop her husband’s grave site. She looks like a college student.

In the first weeks after her husband’s death, searching for someone to blame, she imagined confronting Vowell and other more senior officers. It would take months for her anger to fade.

Lt. Col. Joel B. Vowell: The commander

Vowell, like many members of today’s officer corps, grew up in a military family. His father did two tours of Vietnam as a Special Forces officer and company commander, leading a unit of about 120 men.

At age 17, Vowell headed off to the University of Alabama, determined to become a doctor instead of a soldier. “I saw what it did to my dad,” he said of the Army. “He was home late and gone all the time, and I thought that sucked.”

During his first semester of college, he spotted a couple of Army ROTC cadets on a training patrol. The camouflage-clad students reminded him of home, and he signed up for a few ROTC courses. A few months later, he won a three-year ROTC scholarship. “I liken it to people who find a calling in the clergy,” he said. “The passion hit me.”

He served in Iraq and Afghanistan as a planner and a staff officer before taking command of an 800-man infantry battalion. In April 2010, the unit deployed to northern Konar province, one of the most violent areas of Afghanistan. Vowell’s troops arrived just as the enemy was shifting fresh fighters and resources into the area. He lost nine soldiers in the first two months to roadside bombs, rocket attacks and a suicide bomber.

The battalion fought back with large-scale attacks on enemy sanctuaries along the mountainous Pakistan border. In the valleys, Vowell focused on building Afghan governance and training the province’s army and police forces.

The enemy countered with more men and weapons from the Pakistani side.

Vowell did not want to hand the next American unit the same hard fight that his men faced in their first few months. On March 29, he launched a pre-dawn attack on the enemy’s most remote border sanctuary.

Vowell was hurtling toward the battlefield in a helicopter when the battalion suffered its first three deaths. A rush of emotion ran through his body. “You can feel it,” he said. “It is not pure anger; it is not pure dread; it is not revenge. It is all of the above.”

Later that day, a thick fog rolled over the mountains, forcing the American helicopters to pull back. The enemy used the respite to mount an attack of its own. Arrechaga and two other soldiers from the battalion’s Bravo Company were fatally shot as they were moving to cover.

Vowell had planned to spend the battle with the Bravo soldiers, but the bad weather grounded him at the battalion’s makeshift mountain command post. In many ways, this was fortuitous. It allowed him to manage the battalion’s fight and coordinate its requests for artillery fire and medical evacuation helicopters.

But it also troubled him. “Both the firefights where I lost guys, I was not physically present,” he said.

A few weeks later, he was back at Fort Campbell in the brown-vinyl-sided quarters that he shares with his wife and two sons. He wore four memorial bracelets etched with the names of the 18 soldiers he had lost over the course of his tour. Every time he moved his arms, they gave off a dull, metallic clank.

“Why are you wearing the bracelets?” asked his 10-year-old son, Matthew.

“They are for some men that work with me,” Vowell replied. “They are not here anymore, and I am remembering them.”

“Were they killed?” Matthew inquired.

Vowell nodded, and his son changed the subject. A few days later, Vowell decided to put the bracelets away. He would wear them only on Memorial Day and Veterans Day. “Focus your efforts on those two days a year,” he recalled an older officer advising him in Afghanistan. “Otherwise you will just be kind of erratic 365 days a year.”

Vowell gave up command of his battalion this summer but stayed at Fort Campbell as the 101st Airborne’s operations officer, a highly sought-after position in the division.

He has seen Seana and other widows at the base. In August, the brigade’s commanders unveiled a stone memorial that included the names of the soldiers killed under Vowell’s command, and they gave awards to some of the living. Vowell spotted Seana and a few other widows waiting behind a line of soldiers to see the memorial.

The widows were upset that the awards presentation and the unveiling were merged into a single event. Vowell approached Seana, they talked for a moment, and then he took the widows to the front of the line.

The brief encounter stuck with him. He wondered how Seana and the others would handle the first anniversary of their husbands’ deaths. What would they think when the battalion returned to Afghanistan late next year?

“It looks like we are not winning,” Vowell said of the unit’s impending return. “We are 10 years into this. It’s natural to think, ‘What is it all for?’ ”

He said he plans to take Seana and some of the other widows out for coffee after the Christmas holidays and before the March anniversary. By then, he hopes, he will be able to give her some evidence that the battalion’s tour allowed the fledgling provincial government in Konar province to take root. He would like to show Seana some quantifiable proof that the final assault helped protect the American unit that followed his.

He wants to show her and the other widows that their husbands’ deaths mattered. “I think it is my job to explain the value of what their husbands did,” he said.

At the cemetery, Vowell kneels in the mud and straw at the base of Arrechaga’s grave. He places an embossed coin commemorating the 2nd Battalion, 327th Infantry Regiment on top of the marble headstone. His wife waits a few yards behind him, her head bowed.

Vowell stands, and they head back to their quarters at Fort Campbell.

Seana Arrechaga: The widow

In 2006, Seana (pronounced like “Shauna”) was 19 and visiting Fort Campbell from Ohio when she met Ofren Arrechaga.

He had just returned from his second combat tour in Iraq and been handed divorce papers. He and Seana married in September 2007, and he left again for Iraq 21 days later.

She assumed that her husband’s training schedule and combat tours would dominate their married life. “I knew what the rest of my life was going to look like. Or at least the next 13 years of his career were going to look like,” she said.

The couple lived together for 18 months at Fort Campbell before Arrechaga deployed to Afghanistan in April 2010. Seana stayed with their toddler son in the one-story brick home they rented near the base. She slept with her cellphone on the pillow next to her and spoke to her husband at least twice a day.

Arrechaga, who came to the United States from Cuba in the late 1990s at age 14, had become a standout sergeant. In the summer of 2010, his unit, based at a 120-man combat outpost in Konar province, suffered nine deaths. Vowell removed Arrechaga’s platoon sergeant for poor performance and elevated Arrechaga to the job.

A few weeks later, the platoon leader, the soldier immediately above Arrechega, was replaced with a fresh lieutenant. “Arrechaga held the guys together,” said 1st Lt. Alex H. Johnson, the new platoon leader. “He was my security blanket.”

Seana learned that her husband had been killed at the end of March, just as thousands of soldiers from the 101st Airborne Division began arriving at Fort Campbell from Afghanistan. A few weeks later, she forced herself to stand at the back of the airplane hangar as her husband’s soldiers marched in without him.

The sudden influx of men was almost unbearable. Families on the Army post and in surrounding Clarksville decorated their yards and homes for their soldiers. The base supermarket was crammed with newly returned troops.

“I want to buy some black paint and destroy every ‘welcome home’ sign in town,” Seana said in May.

In July, she attended the battalion’s end-of-tour ball at the Opryland Hotel in Nashville.

“Ofren was really excited about the ball because it was in Nashville and we were going to get a hotel room,” she said. It was going to be his last hurrah with the unit before the Arrechagas left for a new assignment at Fort Benning, Ga.

Seana spent most of the night outside the banquet hall, drinking with one of the other widows from the unit.

Throughout the evening, drunk and distraught soldiers stumbled up to tell her how much they loved and admired her husband. The overtures angered her. “I am not the person you should be crying on right now,” she recalled thinking. “I don’t like showing my emotions to people. That is something I do at home, alone.”

Vowell gave a short speech about the battalion’s achievements and the importance of the mission in which Arrechaga was killed. Seana hovered in the doorway to the banquet hall and listened.

“It was not the time or the place for it,” she said of the speech.

A friend tried to pull her away, but Seana insisted that she wanted to stay. “Let’s go,” the friend persisted. “You don’t need to listen to this anymore.”

For a while Seana blamed Vowell and his superiors for her husband’s death, but no longer. “Ofren was a soldier first, and whether he agreed or disagreed with the mission, it was his job,” she says. “That is the only way I can think about it.”

She wants to know more about what happened to him — from the moment he was shot until he died on the operating table. She has quizzed his fellow soldiers about his final words and read his autopsy report. She is waiting for a copy of the Army’s official investigation of the battle.

“I know what organs were removed during surgery, but I don’t know anything else,” she said.

Seana has stayed at Fort Campbell to be close to her Army friends. On her birthday and her wedding anniversary, the small group, which includes several widows, spread blankets on top of her husband’s grave and drank beers and laughed until sundown. “A lot of times we don’t talk about Ofren at all,” she said. “We just talk about everything else.”

By next summer, most of her closest friends and their husbands will have left Fort Campbell for other Army posts. She knows she does not really belong at the base. “After Ofren died, everybody said, ‘You’ll always have a place here,’ ” she said. “But we don’t. The widows don’t really have a place because our connection to the Army is dead.”

The civilian world seems even more alien. The war that changed her life is largely absent outside military towns and bases. “All of my friends who went to college are living a version of reality that is very different from mine,” she said. “I don’t know how to live in a civilian town.”

In a year and a half, when Alston starts kindergarten, she plans to go back to school.

On Veterans Day, before she leaves the cemetery, she clears away the Halloween decorations and some wilting orange mums. She sets down fresh roses, a Big Mac and a can of Monster energy drink.

Alston leaves behind a piece of paper with an outline of his hand in red crayon and “Happy Veterans Day Daddy!” written in blue.

Vowell’s battalion coin rests on top of the gravestone.