"I believe he is the heart and soul of the film," he says, in a slight break from modesty. "He is an old friend, but like a brother and an uncle. He protects the son (Khalid, played by two young actors) and he dares to speak plain truth to the boy's proud father, Baba (Iran's great Homayon Ershadi)."
The male triangle is the tripod on which rests Marc Foster's rich, sobering film from Khaled Hosseini's hit novel. Or rather, moves in vivid strokes from a peaceful Kabul before the Soviet invasion of 1979 brought in hell, through the Afghan diaspora, with the son and father escaping to America, then the grown son's return to find old Rahim poor but still wise.
"Those older scenes were hard," says the actor. "Here was a man who loved being chic, dressing and living well, now he cannot. But you see the core relationship. When he just walks by the boy, with a little touch on his shoulder, you see the love."
Impeccably creating Old Kabul, soon ravaged by the Soviets and then Taliban fanatics, with the beloved kiting contest going the way of the wind, "Kite Runner" was filmed in northwestern China, "about seven hours' flight from Beijing, near Mongolia. The Kabul of 30 years ago no longer exists, and Afghans who've seen the film say we capture the essence of it from their youth. Many have wept.
"At one point we had 24 nations represented on the shoot, and five translators. Although I've known men like Rahim, I only knew him once I got on the set, put on the outfit, the makeup, and it all came together. The audience is smart, and if you don't deeply believe in the role - not just acting him, but being him, but be him - they will not either."
Though not an Afghan, Toub knows all about the core issues of the movie. His Jewish family left Iran before the 1979 Khomeini Revolution. He was raised in Manchester, England, later finishing high school in New Hampshire before moving to California. And he surely knows the home strictures of old ways.
"At 5, in England, I said I wanted to be an actor. They would hush me: Don't say that! Wanted me to be a doctor or engineer. But the passion for it never went away, and when I wrote my parents from Switzerland, saying I would go to America and become an actor, they said they'd disown me."
His parents still "freaked out" when he attended film school at USC, "and though I tried other jobs, the passion continued." The siren call came quite unexpectedly.
"I met a theatrical agent when I was doing real estate sales in Los Angeles. I was in my 20s, and I was leasing his agency some space and said how I wanted to act. One day he asked me to read a script, while we celebrated the deal.
"So I did, and he said, 'You (bleep)! You've been yanking my chain! And you've never had any training?' I said I had very little."
The man signed him up, had photos made, and after the usual jungle maze of auditions, "hundreds of TV shows and about 40 features later, here I am still doing it."
And so well that, as lovely Lorena sits and watches proudly, he can do a bit of discrete preening about his current work. Not only is he "the redemptive figure" in "Kite Runner," but next year he will be seen in "Iron Man," the big effects extravaganza "where I am Yin-Sen, who sets off Iron Man (Robert Downey Jr.) on his journey. The film looks absolutely amazing."
And he can be seen at Christmas in "Charlie Wilson's War," which also taps into war-torn Afghanistan. His role of Hassan came by way of a very special request:
"I just have a cameo, really. (Director) Mike Nichols wanted me but I was busy with 'Iron Man' and 'Kite Runner,' but then Mike called back to say I should drop in when I could, to 'just come and play with us.' Hey, in this business you don't say no to Mike Nichols."
Nor, soulfully, could he have turned down "The Kite Runner," a film he judges with the passion of someone who has lived it whole. I don't think I could have done this part before. I had to mature into it. It made me really appreciate what I have in life, with all my comforts and opportunities. How lucky I am.
"You know, it is not an Afghan story. It is about any culture which gets broken up. It is life, with its ugliness and beauty, and family, love, betrayal, survival. That is why everyone relates to it."