Mr. Nguyen lives in Silver Lake, a largely Hispanic neighborhood here that has more recently become a hipster hangout. His living room is immaculate, devoid of all personal touches. In one corner are five coffee-table books. They all have “Vietnam” in the title.

“A war doesn’t end simply because we say it does, and a war isn’t simply the things that happen on the battlefield,” he said. “To me, war is a much more expansive beast.”

If “The Sympathizer” was born out of anger, it also grew out of other books. Writers draw inspiration from fellow artists all the time, but with Mr. Nguyen, the relationship is especially tight.

Ralph Ellison’s “Invisible Man” is evoked on the first page. (Mr. Nguyen and his partner, Lan Duong, named their first child Ellison.) The infamous liver scene in Philip Roth’s “Portnoy’s Complaint” is reprised, this time with squid. But “Apocalypse Now” is the most overt influence. “The Sympathizer” is a handsome tribute to one of America’s greatest living directors, or perhaps a punch in the face, or maybe both at once.

“I think if someone were to spend 50 or 60 pages putting me into a novel, I would be amused,” Mr. Nguyen said. “Francis Ford Coppola is a genius in the book. Even if he is flawed.”

That’s a polite way of putting it. At one point in the novel, the director apparently tries to kill the spy by setting a cemetery ablaze. It would be interesting to know Mr. Coppola’s reaction to all this, but he did not respond to a request for an interview. That disappoints Mr. Nguyen a bit. “I’m not afraid of confrontation,” he said.

Mr. Nguyen first saw Mr. Coppola’s film when he was around 10. He was a Vietnamese refugee who spoke fluent English, a bookworm curious about his roots, a war buff like so many boys. He watched the movie alone at home in San Jose on a newfangled VCR.