Tim O’Brien has built a literary career on the Vietnam generation, capturing the experiences of foot soldiers, those they left behind and those who chose not to fight.

From “The Things They Carried” to “In the Lake of the Woods,” O’Brien writes characters stuck in the middle of cultural change and international turmoil, often dealing with regret years after the fact.

His latest offering is “July, July.” The story takes place at the 30-year reunion of Darton Hall College’s class of 1969, and reads like an endnote to his generation; characters confront their own mortality and the deaths of two classmates, and the reunion sparks regret for choices made in the past.

Broom-factory owner Marv Bertel tells a small lie, which lands him in big trouble, and Republican suburbanite Dorothy Stier wonders how her life would have changed if she’d gone to Canada with draftee Billy McCann.

“July, July” continues a common thread in O’Brien’s previous works. In his National Book Award-winning novel “Going After Cacciato,” a soldier decides to leave the war and makes his way to Paris. In “The Nuclear Age,” the main character joins a militant anti-war group instead of joining the Army. Characters seem to make choices O’Brien had considered during the ’60s, and the stories are his musings on how his life would have been if he hadn’t gone to Vietnam.

According to O’Brien, “I had that yearning to run away, and that’s why I came close to doing it, actually. I think everybody has these fantasies about doing what you didn’t do. I went to Vietnam but I thought about how my life would have been different if I’d gone to Canada.

That’s true of ‘July, July;’ for each character fantasizes about what they could have done. It’s how these characters deal with this in their middle age. That’s been a theme in all my work; it’s a human tendency to imagine how things would be different if you decided to be a plumber instead of a dentist.”

O’Brien grew up in Minnesota and attended Macalester College. After graduation, he was drafted into the Army and sent to Vietnam, where he served a tour of duty from 1969 to 1970. His experiences as a foot soldier in the field drove him to write books such as “The Things They Carried” and “If I Die in a Combat Zone.”

“I’m from Minnesota, and you come back from the war, and it’s like going back to a normal Midwestern feeling after you’ve gone through this grim, horrendous thing,” O’Brien commented.

“Nobody wants to talk about it. It’s that Midwestern tendency to look away from the ugly stuff and be optimistic. So it was very tough to get off that airplane and have all these stories you want to tell, but nobody’s interested.

You end up being very quiet and not talking about it. If it hadn’t been for my writing, I’d have been pretty messed up because you can’t hold that stuff inside. Writing is my way to talk about it.”

Although his Vietnam experience was a painful one, O’Brien credits it for the success he’s enjoyed.

According to O’Brien, “It’s a weird thing, but bad things happen to you and that’s where good stories come from, and they always have. For instance, Woody Allen’s comedies come from some pretty grim shit. As an artist, you try to salvage something from the wreckage of experience, and that’s what art’s made of — trying to reach into times of pain and trouble and make a story of it, make it into something people can identify with.

It’s the way of experiencing things that you’re not going to experience in your own life. For me, Vietnam was a terrible, terrible time, yet good stories come out of it.”

These days, O’Brien sticks to an ironclad writing schedule, which he describes as “Pretty depressing for any college student . . . I get up at seven. I’m at work at 8 a.m., work until six, pretty much every day of the week.”

“It’s a job, but it’s a fun job. It took me awhile to get into it. It’s hard to lock yourself in a room every day. It’s like exercise; it’s hard to get into the routine, but once you’re into it you can’t live without it,” he continued.

Of all his previous novels, O’Brien said “July, July” is the one he’s felt closest to, in terms of knowing his characters and the sheer pleasure in writing it.

“I think it’s my best book,” O’Brien said. “I’m really proud of it.”

Tim O’Brien will read from his book, “July, July” at the Orpheum Theatre Thursday at 9 p.m.