Director Ashgar Farhadi

No one expected it, but the Iranian film “A Separation” has taken the United States by storm. Well, a small storm — the film, which opens locally Friday, garnered spots on multiple top 10 lists for 2011, received glowing reviews from critics and audiences and took home the Golden Globe for Outstanding Foreign Language Film. Writer-director Ashgar Farhadi is pretty sure he knows why. “The way people look at the family in Iran is very much like in America,” he says through an interpreter. “That’s the reason Americans get close to this movie, because of the relationship among the family.”

In “A Separation,” Nader (Peyman Moadi) and Simin (Leila Hatami) are ending their marriage because she wants to live abroad (they never mention a country) so their preteen daughter Termeh (Sarina Farhadi) can have more opportunities. However, Nader refuses to leave his father, who is almost completely disabled due to Alzheimer’s. It gets more complicated when Nader is accused of causing his father’s pregnant caretaker to fall down the stairs and miscarry.

While Nader works through the contentious Iranian legal system, “the most important judge in the movie is his daughter,” says Farhadi. “More than anybody, he wants to prove to his daughter that he’s innocent. He doesn’t want the image she’s got about him to be broken.” Ironically, Nader finds that he sometimes has to blur the truth — or outright lie — to remain an honest man in his daughter’s eyes. “In the beginning, he says ‘Wrong is wrong, no matter what anyone says or writes.’ But when it comes to it, it seems very difficult to do what he says,” says Farhadi. “Something that we think is right from a different angle might look wrong — especially about the behavior of people.”

Eventually, Termeh learns that her father isn’t the perfect man she envisioned, and that the world isn’t the cut-and-dried place she thought it was. If mainstream American audiences have seen any film that focuses on Iran, it’s the 1991 Sally Field melodrama “Not Without My Daughter,” the story of an American woman trapped in the country by her Iranian husband. While that film concentrated on the differences between Iranian and American societies, “A Separation” focuses on what the two countries — often locked in political strife — have in common by showing a normal family in a normal, if heightened, situation. Farhadi believes the film gives Americans a unique look at the lives of real Iranians. “We cannot look at the people of a country from a political angle, from the people in power. We must look at all the people.”