It's released in the UK this week and, in the Telegraph, Robert Kaplow, author of the book on which the film is based, has published his notes on the production process.
I meet for the first time, in person, the screenwriters: Holly and Vince Palmo; they’re wonderful and humble and warm-spirited, and they listen. He’s in jeans with longish gray hair, eyeglasses, stylishly unshaved. She’s gracious and a little shy, and she’s a reader: I tell her our hotel is off Bayswater Road, and her immediately response is: “George Smiley lives there.” I like them both immediately, and I sort of apologize for my lengthy e-mails about the various drafts of the screenplay. “You probably thought I was a real officious pain in the ass.” No, they didn’t. And they tell me, at length and with considerable passion, how much they love the novel. They explain to me their process, which was to start by dramatizing every scene in the novel—and then start cutting. Holly tells me that what impressed her was that every scene in the novel was shaped with a beginning, middle, and end. This compliment pleases me greatly, and I tell her that it’s probably a result of having read and analyzed so many plays. We realize that the Palmos are closer to this story than any other reader I will ever have: they’ve weighed every word; debated what to retain or delete. Lynn, who abridges for Random House Audio Books, finds the parallel in what she does: other than the author, no one is closer to the story, sentence-by-sentence, than the abridger; it’s a kind of old-fashioned line-edit.