Some months after 9/11, I received a call from a British women's magazine editor who wanted to commission a feature. "It's about terror sex," she said. I didn't know what she was talking about. "You know, terror sex! Everyone going out and having, like, crazy sex all the time, because they don't know how long they've got before a terrorist attack." I had never heard of this behaviour before, and nor for that matter since, but when I mention the call to Susan Faludi she nods - "Ah, yes, terror sex" - and laughs. "But at least," she points out, "terror sex was about fun. It didn't require going out and buying a rolling pin."

Faludi received her first call from a journalist writing a "reaction story" to 9/11 on the very day of the attacks. She wondered why anyone would solicit her opinion on international terrorism, but after some vague preambles about "the social fabric", the reporter's purpose became clear: "Well," he said gleefully, "this sure pushes feminism off the map!"

The calls kept coming. "When one journalist rang to ask if I had noticed how women were becoming more feminine, I asked her, 'What exactly is your evidence?' She said her girlfriends had started baking cookies." Within weeks the pattern was growing clear. "It was the idea of the return of the manly man, and of women becoming softer. That had become the trend story."

At the time, Faludi was working on a biography of an eco activist. "But I suddenly felt, 'Why am I off in the woods?' when I felt like I wanted to be writing something closer to what was happening." She began monitoring the post-9/11 media closely, and found them dominated by enthusiastic reports of a mass retreat by women into feminine domesticity, and a wholesale revival of John Wayne manliness. Concerned that this narrative bore little resemblance to reality, Faludi shelved the eco biography and set about analysing the motives and evidence - or lack of - for this curiously reactionary narrative. The result is her third book, The Terror Dream: What 9/11 Revealed About America.

I had read that the author of two feminist blockbusters, Backlash and Stiffed, was unexpectedly meek in person. But the first impression is still a surprise, for Faludi, 48, is so paper thin and softly spoken as to seem almost like a middle-aged child. We meet in San Francisco, where she lives with her partner, and her manner is calm and kind, but wary. My early questions widen her eyes, not so much like a rabbit in the headlights as a field mouse.

Faludi's caution may be a legacy from the ferocity of public reaction to her previous work. Ever since the publication of Backlash in 1992, the author and journalist has found herself caught up in America's culture wars, a combat zone to which her sensibility, though not her intellect, seems ill suited. "Backlash was an advocacy book - or at least it was perceived that way," she recalls, almost shuddering. By comparison, she says, The Terror Dream "is not such a barn burner, which is fine by me".

Less a call to arms than a piece of cultural criticism, its thesis is still highly contentious by the standards of mainstream American thinking. When al-Qaida attacked their country, Faludi writes, the humiliating shame felt by American men watching helplessly on TV was experienced, at a subliminal level, sexually. "The post-9/11 commentaries were riddled with apprehensions that America was lacking in masculine fortitude." A Washington comment article panicked about the "touchy-feely sensitive male" who had been "psychopathologised by howling fems", and speculated hopefully, "Is the alpha male making a comeback?" Despite the perversity of a nation "attacked precisely because of its imperial pre-eminence" reacting by "fixating on its weakness", America's media fell back in love with the manly man - an old-fashioned hero strong enough to defend his nation and rescue his womenfolk.

If he did not exist, he would have to be invented. So firemen had to be superheroes, widows had to be helpless, unmarried women had to be frantic to wed and working mums had to want to stay at home. Crucially, strong men had to protect weak women - a desire vividly dramatised by the Rambo-style rescue in Iraq of Private Jessica Lynch, who found herself reconfigured by the media from professional soldier to helpless damsel.

Faludi traces this "rescue narrative" right back to the original shame of America's frontiersmen, whose womenfolk were frequently kidnapped by Indians - and, more shaming still, did not always want to be rescued. "The 'unimaginable' assault on our home soil was, in fact, anything but unimaginable," she writes. "The anxieties it awakened reside deep in our cultural memory. And the myth we deployed to keep those anxieties buried is one we've been constructing for more than 300 years."

Somewhat to her surprise, The Terror Dream has received broadly good reviews in the US. But this, Faludi suspects, has a lot to do with the fact that it was not published until last year.

"You know," she says drily, "you really couldn't say anything questioning in this country for years, not until hurricane Katrina - 9/11 was still too much of a sacred cow. You certainly couldn't make a cynical remark. You saw what happened to Katha Pollitt."

Pollitt was one of a number of women writers, including Susan Sontag, whose tentative dissent from the jingoistic chorus in the months after 9/11 provoked peculiarly spiteful uproar. "Pollitt, honey, it's time to take your brain to the dry cleaners," one columnist sneered; "We're at war, sweetheart," wrote another. A man called Pollitt's home number and ordered her to "go back to Afghanistan, you bitch".

But surely male dissenters could - and in some cases did - incur outrage? "Yes," Faludi agrees, "but the criticism towards women wasn't just: that's an unpatriotic thing to say. It was: that's an unpatriotic thing to say, and you're a bad mother, and you're morally deranged, you're a ditzy idiot. The language was very much coded in female terms. And it was so way over the top. I mean, some of these women hadn't said very much of anything."

Her theory that this signalled the advent of a misogynistic climate has been challenged by some critics, who point out that the period saw the first female evening network-news anchor, Harvard's first female president and America's first female secretary of state. "I mean," objected one, "how can she not mention that Hillary Clinton is the leading Democratic contender for president?"

"I found that really exasperating," Faludi responds, "because this is not a book about what 9/11 did to women. Or to men, for that matter. It's a book about how 9/11 ripped the bandage off, so we could see the underlying machinery that makes the culture go. The media and the rest of popular culture weren't recording people's reactions to 9/11; they were forcing made-up reactions down people's throats. So whether Katie Couric's at the anchor desk on CBS, that doesn't contradict this."

Besides, she adds: "For all the talk of Condi Rice being in a high position, the woman who was most celebrated in the White House was Karen Hughes. And for what? For going back to the home." The presidential adviser stepped down in 2002 to spend more time with her family, a decision deliriously feted as "wise" and "unselfish", under headlines such as "There's no one like Mom for the home". A Wall Street Journal columnist diagnosed "a case of Sept 11", and speculated dreamily on the bliss of Hughes's new domestic future. "She can wash her face in Dove foamy cleanser, pat it dry, put on a nice-smelling moisturiser and walk onward into the day. She can shop. Shopping is a wonderful thing."

More startling even than the retro-sexist nature of the mythmaking exposed in The Terror Dream, though, is the sheer scale of it. Boundaries between fact and fiction appear blurred to the point of non-existence. Time magazine dubbed George Bush "the Lone Ranger", while one political analyst noted that his "evildoers" rhetoric reminded him of the "Whams", "Pows" and "Biffs" of Batman, concluding: "This is just the kind of hero America needs right now." Scaling new heights of self-referential absurdity, the Daily News offered, as evidence for a story about the "opt-out trend": "Talk of married, professional moms dropping out of the workforce to rear kids is all over magazines, talkshows and bookstore shelves." Reporting grew so detached from reality that "security mom" was allowed to become a staple of mainstream media and political discourse, even though Time's lead pollster confessed that, despite searching for this new demographic identity, "We honestly couldn't find much empirical evidence to support it."

As a work of cultural criticism, The Terror Dream is comprehensively shocking. But didn't the extreme disconnection between reporting and reality that it exposed present the author with a problem? If the country's cultural narrative was driven more by fiction than fact, and failed to reflect the truth of post-9/11 America, why base a whole book upon such spurious material?

"Because we live in a culture that's so . . . you can't . . ." She casts a hand around the hotel bar helplessly. "I mean, this is sort of miraculous, to be sitting in a room where there's not some massive flat-screen TV yelling at us. It's almost a sci-fi feeling, this kind of constant bombardment of programmed thought." Its effect is not as simple, she stresses, as "monkey see, monkey do". "But it certainly has a warping effect on how we think about the world, and how we think about ourselves." Journalism became not descriptive but prescriptive - "and that had an enormous effect on our political life, our policy, our nightmarish policy, our misbegotten military strategy".

In one respect, she concedes, cultural criticism today is less relevant than it used to be. "The culture used to move relatively slowly, so you could take aim. Now it moves so fast, and is so fluffy and meaningless, you feel like an idiot even complaining about it." But on the other hand, "I think a reason that a lot of people feel politically paralysed is that it used to be clear how power was organised. But those who have their hands on the levers of popular culture today have great power - and it isn't even clear who they are." They may be commercially accountable, in other words, but not democratically.

The real trouble with cultural criticism, of course, is not unlike the weakness of social "trend" stories extrapolated from catwalk fashions. Difficult to quantify or verify, its connections operate outside the calculus of statistical fact. But as an explanation for how 21st-century America found itself comfortable with rendition and waterboarding and torture, the link from a John Wayne fantasy revival to a "Lone Ranger" cowboy president, to the lawlessness of the wild west, is powerfully compelling.

"We have to fight the terrorists as if there were no rules," a senior New York Times columnist wrote, as if riding into town. "A gunshot between the eyes," advocated another in the New York Post. "Blow them to smithereens."

Does Faludi think, I ask cautiously, that this weakness for muddling up cultural fiction with reality is caused by the sheer volume and sophistication of America's media? Or does something in the national psyche render Americans uniquely susceptible to the confusion? I'm a bit worried that Faludi may feel the conversation is taking an anti-American turn. But she does not do that classic liberal sidestep of going only so far, before retreating into patriotic disclaimers. Her manner might be diffident, but her answer isn't.

"I think," she says bluntly, "it combines with a number of prevailing, longstanding dynamics in the American mindset. You know - the desire to be seen as innocent, that you can just hit the restart button. That tomorrow's a new day, one person can make a difference - all these apolitical, and even anti-political, or certainly anti-historical ways of looking at the world. That makes us more susceptible to Cinderella stories, and want to believe them. Americans have always wanted to believe in some dreamy notion that has nothing to do with the facts that are right before them. Americans are just so wedded to saying OK, let's just turn the page and everything's going to be fine."

At the risk of sounding like a smiley, solution-orientated American interviewer, I ask if she has any constructive suggestions as to how to address the problem articulated in Terror Dream. "I think the solution is actually to talk more about the problem, before saying let's move on. There is this five-minute window that happens after a crisis like 9/11, when people are actually grappling with real experience, and with real feelings of vulnerability and weakness and pain and sorrow. And that's immediately swept aside in favour of this make-believe story line. If we are really to free ourselves from that reflex, we have to understand the reflex - which is going to take more than five minutes. After all, it took us hundreds of years to create it and buy into it."

It's so rare to meet an American who seems gloomier than me, I feel slightly embarrassed to mention our excitement across the Atlantic at the prospect of a new president, for fear of sounding naive. Faludi won't say which way she voted in the Democratic primary - but doesn't she feel optimistic about the forthcoming election?

"Well, most of my voting life I've been painfully disappointed, starting with the first election I was old enough to vote in, which brought in Ronald Reagan. Yes, on the Democratic side we have a woman refusing to be a weak maiden, and we have a male candidate refusing to be the swaggering tough guy. So maybe things have really changed. But on the other hand, this myth never really goes away; it just goes underground, and it's going to come back with a vengeance in the general election. You can already see it."

I ask her what she means.

"Well, let's assume McCain is the Republican candidate. His story is going to be the story of Daniel Boone - the guy who was taken captive by Indians or, in his case, the North Vietnamese, and withstood torture and came back. That's the drama that's going to be trotted out. Already they're talking about 'McCain the Warrior'. And then on the Democratic side, whoever the candidate is they'll be attacked because they don't fit into that rescue formula. Clinton will either be accused of being not manly enough to withstand the terrorist threat, or accused of being too cold and calculating to be a woman. Or both. And Obama will be this scrawny guy who doesn't seem macho enough to stand up to the enemy.

"I don't think," she smiles sadly, "we've seen the last of the narrative"

· Susan Faludi's The Terror Dream: What 9/11 Revealed About America is published by Atlantic Books at £12.99. To order a copy for £11.99 with free UK p&p go to theguardian.com/bookshop or call 0870 836 0875.