Absurdistan, by Gary Shteyngart

Misha Borisovitch Vainberg, also known as Snack Daddy, is a 325-pound ruin of a man, the Puma-wearing, gangsta-rap-fetishising, money-burning only son of the 1,238th richest oligarch in Russia (recently deceased). "Let me tell you something," he laments at the beginning of Absurdistan, "without good friends, you might as well drown yourself in Russia. I'm a modest person bent on privacy and lonely sadness, so I have very few friends." Not only is Misha trapped in his wreck of a body, with its comically mutilated penis (the casualty of a drunken adult circumcision) and its nest of vicious childhood complexes; he's enfolded, too, in the gorged monstrosity of the new Russia, and he can't leave.

Long as Misha may for America, for Accidental College, where he spent years and $2m studying "to become a normal prosperous American", and for Rouenna, his mixed-race girlfriend from the Bronx - "in what other country," he soliloquizes hopelessly, "could we have even existed?" - he can never go back. The State Department have refused him a visa nine times, "on all occasions," he complains, "citing my father's recent murder of their precious Oklahoma businessman". Absurdistan, then, "is my love letter to the generals in charge of the Immigration and Naturalization Service. A love letter as well as a plea: Gentlemen, let me back in! I am an American impounded in a Russian's body."

Things only get worse. While Misha fretfully sates himself on sturgeon kebabs and Johnnie Walker, rapping dolefully with his homeboy, Alyosha-Bob, to the "sensuous ghetto rhythms" of "Ass 'n' Titties" by DJ Assault, away in America his girlfriend is being seduced by the novelist Jerry Shteynfarb (who "thinks he's the Jewish Nabokov").

Misha's hangers-on persuade him that the best bet is to travel with his manservant, Timofey, to the Republika Absurdsvanï on the Caspian Sea, to procure a Belgian passport; there Misha, "a sophisticate and a melancholic", spies the chance he's been waiting for to make a difference in the lives of others. Absurdistan is the ancestral territory of the Svanïs and the Svevos, two sects immemorially divided over the precise angle of Christ's footrest on the Orthodox cross, and it also plays host to the watchful cohorts of Halliburton, KBR and the international petrochemicals industry. When a civil war breaks out, Snack Daddy - by then in bed with the daughter of the local crimelord and appointed "minister of multicultural affairs" by the nascent administration - is caught in the crossfire.

But mere summary doesn't begin to do justice to Absurdistan, an almighty laughing horror of a book that maintains the near-impossible confidence of its style from start to finish. Read it - not only for a lethal satire on globalised values, nor for a stream of immoderately good jokes, but for a demonstration of the kind of unabashed comic maximalism that's been next to non-existent in American fiction since Catch-22. So far, I think, this is by far the funniest novel of the 21st century.