Chasing the American Dream is a theme so pervasive in US cinema – and often beyond – that it scarcely seems like a theme at all: it's the principle upon which much Hollywood storytelling is built, after all. But few filmmakers have done as much in recent years to redefine and recontextualize the Dream as Ramin Bahrani. North Carolina-born, but of Iranian heritage, Bahrani has a distinct personal perspective on life, liberty and the pursuit of happiness that has colored all his work to date: the late Roger Ebert, one of his earliest and most loyal champions, has repeatedly described him as the best American director of his generation.

His first three features – “Man Push Cart” (2005), “Chop Shop” (2007) and “Goodbye Solo” (2008) – were all delicate independent explorations of the immigrant experience in the US. For his fourth, however, Bahrani has made a significant stylistic departure to examine the Dream from the inside: powered by two big-name leading men and embracing robust Hollywood melodrama, “At Any Price” is a searching study of the financial, psychological and generational conflicts roiling the serene surface of America's farming heartland.

“One of the things that interested me about going into the heartland was how different it was from our collective consciousness about it,” says Bahrani. “When I first got out to Iowa, I was thinking how unlike the Terrence Malick vision of that environment – which I love – it had become. There's something so new about it now: the farmers aren't simple folk in overalls with a vegetable garden, but highly sophisticated businessmen, navigating and negotiating very complex structures. All of that seemed, compared to my other films, a fresh way to look at the American Dream, this time from within: the characters aren't immigrants, and they actually have money, yet they're still under a significant amount of pressure.”

Midwestern masculinity takes a hit, too, in a story that shows long-held patriarchal structures – whereby sons inherit their fathers' land, businesses and, ultimately, identities – being challenged by internal and external forms of corruption. Our protagonist Henry Whipple (even his name sounds archetypal) is an Iowan commercial farmer who has successfully brought his business into the 21st century through ethical compromise: opportunistically grabbing land from fading rivals and trading in genetically modified seeds. Small wonder his young son Dean has no interesting in inheriting this grubby enterprise, instead fostering ambitions of being a NASCAR racer.

The morally fraught battle for mutual understanding that ensues between these two stubborn, only superficially different men is by no means an exclusively contemporary one: no attempt is made to disguise the influence of Arthur Miller's “Death of a Salesman,” for example, while Bahrani admits to the influence of great American filmmakers from George Stevens to Robert Altman. The star casting, meanwhile, is particularly canny, as Bahrani picks two all-American heartthrobs to reflect both each other as well as the ideals of their society: as Dean, Zac Efron's bright-eyed wholesomeness takes on a bitter edge, but it's Dennis Quaid, as Henry, who carries the film's chief dramatic burden: a foxy salesman who nonetheless senses his powers of persuasion waning in the face of his son's contempt, he's a slicker modern answer to Miller's Willy Loman.

“Ramin and I talked about Loman from the very beginning,” says Quaid, his typically chipper demeanor ever-so-slightly slowed by tiredness: he's come off eight weeks of shooting “Vegas” for TV. “Like him, Henry's a character who has been chasing the American Dream and become corrupted in the process. As a salesman, he has to project a public face of confidence, but because he's under the rule of a corrupt system, you gradually see the self-loathing beneath. He's actually quite unlikeable to begin with, and that ambiguity interested me. I don't think the film has an agenda. Ramin's films never do: they're really just out to hold a mirror up to life.”

I mention to Quaid that his portrait of Henry reminded me of another of best performances, as a closeted 1950s family man in Todd Haynes's “Far From Heaven”: the two characters ostensibly have little in common, but share a kind of weariness with the authoritative masculine role society has dictated they play.

“I thought a lot about that character too,” Bahrani adds. “They're both so conflicted, and there's something so physical about the way Dennis projects that conflict – I recognized that on set, but didn't realize how calculated it all was until I was in the editing room. Then I could see more what he was up to in terms of details like how he held his shoulders, how he clenched his fists, the movements and mannerisms of his face, and when he'd allow cracks in the salesman performance to appear.”

“As a character, he grew more interesting for me the more pressure he was put under,” agrees Quaid. “It's definitely a generational story: after all, this farm has been passed from father to son for years, and when Henry finds that his son doesn't want it, that upsets the order of things. And Dean sees his father as a pathetic figure – everything he doesn't want to be, but already is to some extent.” The older star reserves particular praise for Efron's performance in defining this conflict: “He's really excellent here... Zac has all the tools in his toolbox to be a great actor.”

Guy Lodge is a South African-born critic and sometime screenwriter. In addition to his work at In Contention, he is a freelance contributor to Variety, Time Out, Empire and The Guardian. He lives well beyond his means in London.