He became involved in a couple of Army Air Corps historic associations, enjoying the camaraderie of the airmen, who understood his night terrors and late-diagnosed PTSD. These society gatherings continued in dwindling numbers until about 2012. Now, as far as he knows, he is the only member from World War II.

Eventually, his daughter Kazuko Spiegel introduced her father to the woman who would become his third wife, JoAnn Bastis, a real estate agent she had met in Westchester social circles. They would be married only for a few years before she died in 2018, though the couple traveled in Europe together twice, including a visit to Reczyn, the tiny village where he belly-landed in 1945.

Mr. Spiegel now lives in a large apartment building with a doorman and a magnificent view of Central Park. Although artificial trees descended from Mr. Spiegel’s designs are found in close to three-quarters of the American homes that put up Christmas trees, he doesn’t keep a tree himself.

He raised his children to take pride in their Jewish-Japanese heritage, and he still makes the Hanukkah latkes for his grandchildren. But when his children were young, they always had a tree, first a real one, and then the best of his fakes. “Do you think Christmas trees were really a religious symbol? They were pagan symbols. My kids liked them.”

When asked what he would like his legacy to be — artificial trees or military heroism — he closed his eyes.

The war, he admits, was probably the most exciting time in his life. Who’s left to talk about it with, though?

“I can tell you this,” he finally said. “We fought against fascism. We fought against Hitler’s desire for a master race.”

He is surrounded by pictures of his children and his grandchildren, and he worries about growing racism. “I never thought that fascism was a possible threat to our nation’s democracy until now,” Mr. Spiegel said. “Right now, however, all I’m trying to do is stay alive.”

Laurie Gwen Shapiro is the author of “The Stowaway: A Young Man’s Extraordinary Adventure to Antarctica.” She is currently writing about Amelia Earhart’s marriage.