The Punisher, Marvel’s most lethal vigilante, is just as compelling when he’s not in action.

What gnaws at him when he believes that his war against corruption — which contributed to the murder of his family — has ended?

“What do you do when you put that skull down, and you go back to living your life?” said Jon Bernthal, whose character debuted last year on Netflix’s “Daredevil,” and now has his own series on the streaming network.

Bernthal has talked with combat veterans about how they handle the brutality of war. And he said he’s built a bond with many in the military who are fans of his portrayal of Frank Castle, aka the Punisher.

They especially like how he conveys the character’s sense of loss and the symptoms of post-traumatic stress disorder.

“One thing I’ve heard from a lot of people who have gone through severe trauma in combat is that when the fight’s on, and when you’re on mission, your training kicks in and you know exactly what you’re doing and you’re moving forward,” Bernthal said. “But it’s when the mission ends, it’s the quiet afterwards. It’s going to sleep. It’s returning home.

“That’s when the war inside begins.”

On “Daredevil,” the character retained an air of mystery as a side character, largely because the show was focused on the title superhero. But in “The Punisher,” writer/producer Steve Lightfoot aimed to show Castle’s difficulty with coping with life, Bernthal said.

“They wanted to create a well-rounded, three-dimensional character vs. this guy who sort of just lives in the shadows. What does he do when you bring him into the light?”

Netflix and Marvel had planned to debut “The Punisher” this fall. But after shooting incidents in Las Vegas and Texas, they decided to cancel their appearance at New York Comic Con and postpone the release of the series out of respect for those connected to the tragedies.

Bernthal agreed with the decision to delay “The Punisher,” which leans heavily on the armed violence and brutal combat of the comic book series.

“What happened in Texas and what happened in Las Vegas weighs on me, period,” he said. “It weighs on me as a father. It weighs on me as an American. It weighs on me as a man.”

He said he also hopes that his show can be a part of a requisite conversation about gun control in the United States.

“There’s no end in sight. Unfortunately, in this country right now, I think rigor and steadfastness in your political position has totally trumped being rational and talking about the issues,” Bernthal said. “Both sides of this issue have real merit. I think opposing views and listening with an open mind and an open heart, I think that’s strong. That’s patriotic. I think that’s American.

“As far as the show is concerned, I think art at its absolute best holds a narrative to society and begs society to start asking questions of itself. I don’t think it’s our place to answer those questions. I think it’s our place to ask them.”

And more personally, Bernthal said, “I think we have to start approaching each other with much more tolerance and much more patience, and we need to start admitting to ourselves that we have a real crisis on our hands.”