Jason Isaacs, the British actor who attended the Jerusalem Jewish Film Festival at the Jerusalem Cinematheque to present his latest film, Good, is Israeli - almost. His parents and brothers made aliya years ago and live in Herzliya (although his brothers have moved back and forth between here and England). And like many Israelis, he defends Israel passionately in public and criticizes it passionately in private. "Spiritually, I feel Israeli," says the actor, and the tension between his identification as a Jew who is (nearly) Israeli and a cerebral British actor is evident as he speaks. Like many well-educated British actors (he studied law at Bristol University before turning to acting), he talks a mile a minute, his sentences filled with a vocabulary that would send most of his Hollywood counterparts scurrying for the dictionary. But he also talks with his hands and gets in self-deprecating jokes at every juncture. Talking about Good, he says that making this story of two friends, whose fates diverge widely when the Nazis take power in Germany, was "overwhelming." The film, which is based on the play by C.P. Taylor, stars Viggo Mortensen as a literature professor who is slowly seduced into Nazism in order to advance his career. Isaacs is Maurice, his Jewish psychoanalyst friend, a buddy of his from World War I. "I thought I was steeped in this history," says the actor. But reading diaries of Holocaust victims, Isaacs realized that the "key was becoming one specific individual." The film was not shot in chronological order, so to make sure he knew in detail what was going on with Maurice in every scene, he made a timeline of events. "I needed to know that in this scene, it's 1933, so he's still out drinking and f---ing every night. Now it's 1938, so he can't work. Does he still have a housekeeper, is he sending his clothes out to be dry cleaned or is he washing them and patching them at home? The specifics of the character made it come alive." It was crucial to Isaacs to make Maurice "not a victim, but a lover of life." Making Maurice so real was not an easy process, but Isaacs did what he had to in order to be "truthful," including withdrawing from the social life on the movie set. Part of his preparation included listening to a BBC recording of a Jewish chaplain, Leslie Hardman, who liberated the Bergen-Belsen concentration camp with British troops and conducted a Shabbat service there. Isaacs found the recording moving, and was amazed and delighted to meet 96-year-old Hardman last year at the National Holocaust Memorial Day services in England, where he was a presenter (Hardman has since died). Meeting this man whose life had touched his in such an unexpected way made Isaacs realize, "If my grandparents hadn't been allowed off the ship in Liverpool, they would have been people in those black-and-white [Holocaust] photographs." BUT AS good as Isaacs is in Good, he is probably best known around the world for his role as the evil Lucius Malfoy in the Harry Potter series. Asked whether this character is good for the Jews, he laughs. "Unfettered fun" is how Isaacs describes the experience of playing the Malfoy. For a moment, he talks about Malfoy's focus on "racial purity - it sounds like right-wing political campaigning," but then he says, "I don't want to look at the serious side of it. It was too much fun. It was an opportunity for me to play like my kids play, and to chew up the scenery with some of the greatest actors in the world... They prove that it's not true that an unhappy film set makes for a good film... "We had a ridiculously good time making them," he says, recalling specific scenes with Richard Harris, Robbie Coltrane, Ralph Fiennes and, of course, Harry himself, Daniel Radcliffe. Talking about how the last book is set to be made into two films, he says ominously, "I think that's a mistake." After a beat, he adds, "It should be made into 10 films so I can do it for the rest of my life." His next film, though, is not another Harry Potter movie, but Green Zone, a thriller about American soldiers in Iraq, early in the war, with Matt Damon. Directed by Paul Greengrass (United 93), he calls it a "really nail-biting thriller." He also stars in the television series Brotherhood, but jokes, "I did one episode of Entourage, and I got calls from everyone I've ever known. So I say, 'Did you see Brotherhood? I'm starring in that...' and they say, Oh, yeah, I Tivo-ed it." The actor says he would love to work in Israel, but isn't sure how he could make a living here. Calling all Israeli directors: Write an English-language part for Isaacs, and let this actor spend some time on the beach with his family.