Two radical projects of reappraisal emerge as you make your way through the nearly 800 pages of Ben Marcus’s anthology of New American Stories. One has to do with what it means to be American; the other, at the risk of sounding grandiose (though a little grandiosity seems justified for once), with what it means to be human. I’m not sure how intentional they are: Marcus’s ambitions appear, rightly, more about providing intense literary experiences than making large editorial statements. He calls the book “not a museum piece” but (and note the careful wording) “a sampler of behaviours and feelings we can very nearly have only through reading”.

In a sense it is just that – a sampling of the last 10 years’ worth of books, magazines and small press publications, featuring most of the current eminences of the American short story, from Lydia Davis to George Saunders, along with emerging stars such as Rivka Galchen and Wells Tower, as well as a healthy number of relative unknowns. But necessarily provisional as it is, and clearly favouring a certain aesthetic, it accumulates an unexpectedly powerful coherence as it goes along, achieving the sense – rare in this kind of anthology – of amounting to more than the sum of its parts. It’s a book to wrestle with as well as enjoy; one that forces you to assess and reassess your own sense of what makes a story any good – even of what makes a story a story. It is, indeed, far too quirkily alive to be a “museum piece”, but it feels to me like some kind of landmark all the same.

To start with the “American” aspect. Rose-tinted or not, the image US had of itself before the 9/11 attacks was, in hindsight, fundamentally benign, and the literature generally reflected this. The typical protagonists of an American story from that hard-to-remember era may have been tragic, wounded, haunted by demons, capable of great folly or even terrible violence, but their creators’ attitude towards them was generally sympathetic, and the style of portraiture was essentially ennobling. However flawed those characters were, the ideal they implicitly lived by – still best summed up as Life, Liberty and the Pursuit of Happiness – was seldom questioned in itself.

Judging from the authors gathered here, that era is over. The global disillusionment with America has been thoroughly internalised by the nation’s writers. It’s not so much that the stories are diatribes (though a few come close); rather that an assumed iniquity now attaches itself to the idea of the US as a political entity, more or less automatically. From the first, calmly devastating story, “Paranoia” by Saïd Sayrafiezadeh, in which the life of an undocumented teenage immigrant unravels against a backdrop of bristling flags and looming war, the book steadily crystallises a vision of the US as a locus of callous narcissism, exclusionary greed and militaristic aggression.

“Blink and you might miss this war,” a newscaster smugly declares in that story. Subsequent stories are set against the fallout from that catastrophic miscalculation. Battle-damaged veterans wreak various kinds of havoc on the domestic front in pieces by George Saunders and Mary Gaitskill. In both cases the rote phrase “thank you for your service”, uttered by the civilians they encounter, becomes the convenient formula for avoiding the uncomfortable facts concerning the actual nature of that service. A returning soldier in the Gaitskill story spells it out: “You need killers like me so that you can go on having all the nice things you have.” A more apocalyptic tone prevails in Joy Williams’s wonderfully strange “The Country”, where a man tries to put up a billboard quoting Tagore’s words, “The Mightiest Empire Is Overtaken By Stupor”, among the roadside ads for gun shows and mobile phones. Even in stories ostensibly about other times and places, such as the dystopian, post-plague China of Maureen McHugh’s “Special Economics”, the underlying subject usually turns out to be American malignity, in this case the specious virtue of “green” consumerism, driving a return to indentured service in a company manufacturing bacteria-fuelled batteries: “Americans like them, you know, because of the no‑global-warming … ”

Several stories pursue this idea of culpable innocence, or guilt-at-a-distance, in a more fabulistic mode, with elaborate conceits involving avatars, virtual selves and other forms of surrogacy. Charles Yu has a Swiftian take on outsourcing in “Standard Loneliness Package”, where rich Americans pay to have their negative feelings experienced by drudges in a company in Bangalore: “I feel pain for money. Other people’s pain. Physical, emotional, you name it.” Privileged teens in Kelly Link’s “Valley of the Girls” have a sort of slave-self – a “Face” – to handle the more tedious aspects of growing up, leaving the brats free to concentrate on building their personal pyramids for an eternity of partying in the afterlife. In Lucy Corin’s seriously bizarre “Madmen”, there’s a rite of passage in which pubescent girls visit an asylum and pick out a lunatic to bring home, complete with harness, to install as a sort of tutelary garden gnome: “The whole idea,” as the teen narrator puts it, “is that you take home a madman and that teaches you about Facing the Incomprehensible and Understanding Across Difference.”

We’re a long way from the chaste minimalism and “dirty realism” of the 1980s and 90s. Where those stories described the stoicism and quiet desperation of ordinary people in a plain style that looked back to Hemingway and Chekhov, these baroque, knowing, hyper-ironised creations draw on genre fiction, YA novels, satirical TV shows and standup comedy. Here and there a more classically founded approach does still show up – it says something for the book’s eclecticism that it can accommodate the refinements of Deborah Eisenberg’s coolly impassioned “Some Other, Better Otto”, with its Jamesian emphasis on precisely articulated emotional distinctions, alongside the poppier stuff. And it’s heartening to see, in Yiyun Li’s intimate study of the effects of sexual politics on individual lives, that an unadorned realism learned from writers such as William Trevor can still deliver the modern world as powerfully as any other method.

But as the book progresses you notice a definite leaning towards a more brashly stylised aesthetic. It isn’t always convincing. At times it comes over as a desperation to sound hip, raw, transgressive, original at any expense. Taste comes into this, of course, and some readers will be enthralled by lines that I find annoyingly mannered. A good litmus test might be this, from Tao Lin’s “Love Is a Thing on Sale”: “All the moody emptiness inside of them swelled and joined, and then ensconced them, like bubbles, and there, inside, they floated – the qualmish, smoked-out bodies of them, stale and still and upside-down.”

But it’s very much in this stylistic restlessness that the attempt to grapple with certain shifts in the collective sense of what it is to be human manifests itself. “People aren’t machines,” a character says in Sam Lipsyte’s story, dismissing a sort of proto-Facebook concept being pitched by another character, only to be contradicted by his cannier interlocutor, “ … machines are exactly what people are.” Integers in networks and systems, replicable sets of consumer habits, lesser versions of our own computers – whatever the implied idea of humanity, the old belief in individual consciousness as something uniquely fascinating and worth the effort of getting down on to the page seems to be fading. Without it, verbal energies that might have once gone into psychology and emotion go elsewhere: sociology, high-concept metaphors, lavish effects of narrative voice. Saunders’s aggressively reductive style – on display in his own cartoonish “Home” – is an obvious influence. It’s a kind of brilliance, for sure, but brilliance in the manner of The Simpsons or Family Guy. The human subject flattens, diminishes. It has to: the stories simply wouldn’t work with anything more three dimensional.

There’s a lot of this kind of brilliance on offer in New American Stories. I don’t mean that disparagingly: I wouldn’t admire the anthology so much if I didn’t find some of the things in it hard to take. They are a large part of its provocative immediacy. But the real glory of the book, for me, are the pieces that miraculously seem to have it both ways: Donald Antrim’s manic (in every sense) four-way romantic farce, “Another Manhattan”; Denis Johnson’s laconic set of variations on the idea of confusions and mistakes, “The Largesse of the Sea Maiden”; perhaps a half-dozen others. These manage to feel at once absolutely contemporary and timeless.

• James Lasdun’s Give Me Everything You Have is published by Vintage. To order a copy for £11.99, go to bookshop.theguardian.com or call 0330 333 6846. Free UK p&p over £10, online orders only. Phone orders min p&p of £1.99.