Editor's note: CNN Contributor Bob Greene is a best-selling author whose 25 books include "Duty: A Father, His Son, and the Man Who Won the War" and "Once Upon a Town: The Miracle of the North Platte Canteen."
(CNN) -- And then there were 10.
"I think this is probably our last reunion," said Howard Van Schoor, 86, of Mentor, Ohio. "I wish it could continue, but we're getting shorter in numbers."
At a hotel where I was staying near an Ohio interstate highway exit, I had seen a small group of elderly men having breakfast together each morning. In front of the little area that had been reserved for them was a placard with a military insignia and the words: "Blood and Fire."
I would see them in the elevators; I introduced myself, and found out that this was the annual reunion of the 63rd Infantry Division that, in World War II, had fought its way through France and Germany. Fifteen-thousand American soldiers in that division had crossed the ocean to Europe; the men I spoke with said that some 1,100 had been killed in combat, with many thousands more injured, some grievously.
The ones who were lucky enough to make it home after the war began having reunions in 1947. They were large events during the 1950s and into the 1960s; 500 or 600 veterans of the 63rd Infantry would convene for regional gatherings, and would bring their families. Sometimes, the men told me, there would be thousands of people at the get-togethers.
Ten soldiers were well enough to come to the national reunion this year.
"They would love to hold onto it," said Mary Fran Collier, the daughter of former infantry sergeant Bill Byrnes, whom she had accompanied to the reunion. "But this will almost certainly be the final time. With so few of the men who are still alive and able to attend, we don't even have a large enough group to get a good rate at hotels."
Her dad -- 86, a retired carpenter who lives in Oak Lawn, Illinois -- said he was 18 when he went into the service. Fighting in Europe, he said, "You had to depend on one another for whether you lived or not. When you lost one, it was like losing a brother."
That is why the reunions have always meant so much to him: "We went through the same things, and we're the only ones who can understand that. When you're getting shelled together ... the lucky ones who made it through, it's just so good to see each other every year. You're just so glad to see them."
They were riflemen and artillerymen and mortarmen during the European campaign; they slept out in the open when the temperatures were below zero and when the temperatures were 80 degrees, they sometimes had to go weeks without bathing, they dug foxholes for shelter and ate cold rations and dreamed of home. They encountered, and helped to liberate, Nazi concentration camps and, the indelible horror fresh in their eyes and in their minds, they fought on. Young men then, they often feared that they would never have the chance to see their families again.
At the dinnertime banquets at the three-day reunion this year, even with family members and an honor guard present, there were only around 35 people in the room. A ventriloquist entertained the old soldiers one night; at one meal there was a combo playing songs from the 1940s.
In the weeks since the reunion, I have kept in touch with some of the men and have spoken with them some more. They told me that the motto of their division -- that "Blood and Fire" line -- derived from a wartime speech by Winston Churchill, in which he said that the Axis powers would "bleed and burn in expiation of their crimes against humanity."
The men know that very few people remain who recall the duty of the 63rd. But their pride in their combat remains fierce.
"This division accomplished everything it was asked to do," said Edward F. Fowle, 88, of Springfield, Ohio, who was 19 when he went in. "Never gave up an inch of ground, literally or figuratively."
The men said they hope that American military men and women who are serving around the world right now will someday find the same comfort and warmth when, 50 or 60 years in the future, their own surviving numbers grow small, and they are able to get together with those who fought beside them: with the people who know best what they went through, who shared such an arduous and defining part of their young lives.
"The feeling is still there," said Dr. Jack Linscott, 86, a retired family physician in Marysville, Ohio, who enlisted when he was 17. "We have something in common. We counted on each other then, and we still do. It helps to know that there is someone who will watch your back."
At the hotel the men sat and talked quietly. Some walked slowly; other guests at the hotel either waited patiently, or hurriedly walked around them, intent to get where they were going without delay.
"My eyesight isn't too good anymore," said Howard Van Schoor. "But I like seeing these friends every year. They protected me, and I am grateful for that."
During the war, Bill Byrnes said, when a member of the 63rd would die in combat, replacement troops would be brought in. "After a while, we learned not to get too friendly, in a way," he said. "Because we knew that it would be breaking up your heart again when one of them goes, too."
The end of the reunions is something the men say they know they will have to accept. "We don't cry on each others' shoulders about it," Jack Linscott told me. "The feeling is that it has come to this, and there's nothing we can do about it."
They understand that in the end, as at the beginning, they have each other.
"The kinship is not something that you set out to form," said Edward Fowle. "It's just something that happens.
"There is a bond between infantrymen."
Follow CNN Opinion on Twitter.
Join the conversation on Facebook.
The opinions expressed in this commentary are solely those of Bob Greene.