Less is more for De Niro. Sure, at just over 2½ hours, “The Good Shepherd” takes its time telling the inside story of the CIA’s creation, but the film’s helmer says he wasn’t interested in making a white-knuckle spy story — or a political statement.

It was realism that mattered, which meant stripping away anything that compromised believability: No explosive confrontations, no humorous asides, just business.

“I especially like the scene with Angelina (Jolie) and Matt (Damon) and their son, when they come together before the wedding, and all of that sparse interaction — it’s what’s going on and not going on,” says De Niro.

Though this is only De Niro’s second directorial outing, the thesp saw it as a stepping-stone to another project with the same screenwriter, Eric Roth.

“We came to an agreement, in theory, that if we made the ‘Good Shepherd,’ we would do a second part of the story, which picks up from the Bay of Pigs and the (Berlin) Wall of ’61,” says De Niro, who hopes to follow the same characters further into the Cold War.