Which director would you like to work with that you haven’t before?? “David Lynch. He’s got his own little reality, and I’m interested in it.”

How do actors balance commerce vs. art?? “You just kind of go back and forth. There’s no balancing and no point where the seesaw is even. You run to one end, and then you run to the other. You touch all sides.”

Up next: “Nothing. In order to allow for different experiences to happen, you have to wait. The idea that is way out in left field is the one I’m most interested in, and those don’t come along that often.”

“When I first looked at it, my role seemed to go more in the gung-ho Marine territory,” says Peter Sarsgaard about his perf as a sniper in Sam Mendes’ military drama “Jarhead.” “Then it became more like somebody who didn’t realize the value of their experience until it was being taken from them.”

Sarsgaard could relate, since he was hesitant to enlist for the adaptation of former Marine Anthony Swofford’s bestselling 2003 book about his tour of duty in Saudi Arabia and Kuwait.

“My initial reaction was that I was exhausted. I had just done two movies and I was in the process of doing another. But I was intrigued because of Jake (Gyllenhaal) and the movie’s topic,” reveals the 34-year-old Sarsgaard, who has kept himself awfully busy of late, appearing in four pics this year and two in 2004. “In the end, it was incredible. It was one of those experiences that after you finish it, it’s more remarkable than while you’re doing it. It’s like camp. While you’re there you’re like, ‘I just want to go home,’ and when you’re home you’re like, ‘That was so great.’ ”

From buzzworthy perfs in movies such as “Shattered Glass,” “Garden State” and “Kinsey,” Sarsgaard has become known as a trusted support player. “Jarhead” is no different, in part because Sarsgaard was able to develop the character.

“The role was not clearly defined, as Sam readily admits. And there’s something interesting about diving into the unknown and figuring it out later, especially with Sam because he’s so open to ideas,” says Sarsgaard, who didn’t bulk up for the role and smoked (a sniper no-no) in the movie when he noticed the on-set trainer did. “Marines look 20 million different ways. They all don’t look like they’re on the Zone Diet. What’s nice about having the real guys around is that you figure out how the rules are broken.”

Sarsgaard, born to a military family on an Air Force base, was even able to put a very personal stamp on the role with a shout out to his father.

“There’s this (scene) where I say his call sign. I say ‘Romeo, Golf, Charlie, Romeo, Golf, Charlie.’ That’s my dad’s. He was watching it and he was like, ‘What?’ I like adding those touches.”