FORT CAMPBELL, Ky. — Signs of the season have been everywhere at Fort Campbell High School over the last couple of weeks: a student soloist sang the Carpenters’ “Merry Christmas, Darling” at the annual holiday concert, a big tree sparkled in the cafeteria under the Screaming Eagle emblem of the 101st Airborne Division, and thousands of parents were deployed yet again in Afghanistan.

It is nothing unusual for Alexandra Alfield, a 17-year-old senior whose father, a Special Forces soldier, has been gone since August and for six of the last nine years. “I do miss him,” she said, “but I’m just so accustomed to it.”

As President Obama considers how quickly to withdraw the remaining 66,000 American troops from Afghanistan, the parents of Fort Campbell students are still going off to war.

Nearly 10,000 men and women from the 101st Airborne, a third of the active-duty troops based here, are either in Afghanistan or getting ready to go. Still more parents here have been deployed with units like the Fifth Special Forces Group and the 160th Special Operations Aviation Regiment, known as the Night Stalkers, whose members piloted the helicopters in the raid that killed Osama bin Laden.

That has made the high school, which is run by the Defense Department and is one of only four secondary schools on military bases in the United States, something of a window into the pain, pride and resentment felt by the families of the all-volunteer military force, which has borne the burdens of 11 years of war.

The high school, which has about 700 students and is open to any 9th to 12th grader who lives on the 100,000-acre post along the Kentucky-Tennessee border, is by definition physically and psychologically cut off from the world outside the gates. But at no time is that sense of isolation more acute than now, when many of the students’ parents are deployed while the rest of the country’s interest in Afghanistan has moved on.

“No one really cares,” Tyisha Smith, a 19-year-old senior, said of the outside world. “Your father goes, gets deployed. War — it’s normal. It’s not like a big deal that we’re still at war.”

But Ms. Smith said she was struggling to manage the pressures of her final year in high school while her father was away and she was living with her stepmother. The reality of his deployment with the 101st Airborne is never far away. “It’s starting to hit me that there’s a possibility that he could die,” she said. “I just hope he comes home.”

School administrators point to a bright spot: not as many parents are gone this year as there were at the height of the Iraq and Afghanistan wars, when nearly everyone in the school had a parent deployed and the post was a virtual ghost town. But that hardly makes the modest one-story school typical.

A strict dress code bans jeans and T-shirts, so students wear tucked-in collared shirts with khakis or dark pants. Presidents turn up a lot: Mr. Obama spoke at the post in May 2011, and George W. Bush visited three times while he was president. Vice President Joseph R. Biden Jr. met earlier in 2011 with the Fort Campbell High School football team. And the death of a parent is something to be mourned but overcome.

Only months after his father was killed in Afghanistan in June 2008, Josh Carter, a starting linebacker, helped lead the Falcons to their second of three straight state championships.

“My dad would want me to keep going,” Mr. Carter, now a student at Western Kentucky University, said in an interview over the summer. Administrators say that perhaps five other students have lost parents in the wars in recent years. Many other parents have been wounded or have received a diagnosis of post-traumatic stress disorder.

The students readily call their school a “bubble,” both comforting and claustrophobic, because of the dangers their parents face. “If you went to off-post schools, you couldn’t exactly talk to a teenager because they wouldn’t understand what you’re going through,” said Larissa Massie, a 17-year-old senior whose father is home but has had two deployments to Iraq.

Other students — who know that more than two million service members have served in Iraq and Afghanistan over the past decade, about 1 percent of America’s adult population — are sometimes shocked when they meet counterparts from other schools.

“I talked to one kid who thought we were out of Afghanistan,” said Brittany Gossett, a 17-year-old senior whose stepfather, a Black Hawk pilot, is scheduled to be in Afghanistan until the spring. “They thought we were just peacekeeping and stuff.”

Peacekeeping is hardly the mission of Eileen Sullivan’s father, Col. Tim Sullivan, who is on his third deployment, this time to the dangerous Afghanistan-Pakistan border, as deputy commanding officer of the 101st Airborne’s Third Brigade Combat Team. Ms. Sullivan, a 17-year-old senior, lives at the top of the post’s hierarchy in a spacious clapboard house on a tree-lined street where other colonels and generals live. Her father was also gone on Christmas in 2003 and 2005, in Iraq.

“It’s definitely getting harder as the war keeps going on,” Ms. Sullivan said last week.

First in the senior class, Ms. Sullivan has been accepted to the Naval Academy and is waiting to hear from the Military Academy at West Point, her parents’ alma mater.

Like other students at the school, Ms. Sullivan said she was drawn to a military career despite the strain of her father’s deployments. Military leaders worry that making war into a family business only adds to the divide between the military and the rest of the country, but to Ms. Sullivan it is a culture she knows and admires.

“The military just makes you into a whole person,” she said. “My military role models have everything from physical strength to mental and emotional strength because of what they deal with on a daily basis.”

She hesitated to criticize students who have civilian parents — “I don’t want to say that kids in other schools don’t understand what sacrifice is,” she said — but she added that she was proud that her family chose a path that a vast majority of Americans avoided. “I definitely feel like the people who do it are called to a higher purpose,” she said.

One thing that neither she nor the rest of her family wants is sympathy at Christmas simply because her father is doing his job.

“When you’re out in the real world, it’s ‘Oh, I’m so sorry, it must be so hard,’ ” said Kate Sullivan, Ms. Sullivan’s mother. “You appreciate they care, so it’s a hard balance. But who wants to be somebody that somebody feels sorry for?”

Even so, most of the students — and parents — said it was long past time for the war to end.

“It’s pointless fighting,” said Joshua Orellana, an 18-year-old senior whose father has deployed twice to Afghanistan and is scheduled to go again next year, when Mr. Orellana knows his worries will start.

“It’s just that small thought in the back of my head saying that we could get that call saying that he’s gone,” he said. “And then I have to compose myself so that I don’t show any weakness to anyone else.”

Lydia Schoonover, the school’s choir and piano teacher, said she selected “Merry Christmas, Darling” for the concert because of the lyrics — “We’re apart, it’s true” — and as a tribute to the students with parents away at war. “It’s a fact of life for them,” she said. “They do whatever they’re called on to do.”