SOMETHING HAPPENS when you stay too long in the suburbs. Those inclined to harshness see it as a kind of dry rot, a slow and dusty torpor of the soul that accommodates itself all tooeasilyto the relentless affluence of Scarsdale and Grosse Pointe, to a world of shopping malls and Little League coaches and bitching at the mailman. Even at its best, suburban life breeds a brand of insularity, an isolated arrogance of comfort, that forces its own visions of itself into small places, like bedrooms and garages. Small places and small horizons--no better way to chronicle this world of great, elastic satisfaction. And so if you stay there too long, your eyes start to go and the horizon closes in even more, and all you see is yourself.

John Updike, happily, has gotten out in time. For 20 years Updike and his mellifluous prose have wandered through suburbia, exploring the desiccated guilt and lust of the well-off with a familiar eye. Updike, to be sure, became master of the art, rivalled only by John Cheever, but his recent novels had lost their fire--less compelling, almost tedious, they droned on, as if to say You have read my life so many times before, what more can I say? The painful autobiographical power of Couples petered out to a sense of dry boredom in A Month of Sundays and Marry Me; the horizons were closing in, and all Updike's readers got to see was the author himself, pounding away at a life and times that had already become commonplaces. And so Updike did what he could, which was to get out, or at least to take his imagination and will himself out, and over into the land of big unwashed horizons. Africa.

The Coup, the product of this new perspective, is quite simply a marvelous book. The tale of a coup in the mythical sub-Saharan dictatorship of Kush--"a constitutional monarchy with the constitution suspended and the monarch deposed"--becomes for Updike the vehicle of a biting, driving wit, a brilliant farce that together lambastes America, the Soviet Union, radicals, bureaucrats, poets, capitalists and, of course, lovers. Being Updike, the author retains enough of his obsession with bedroom mores and manners to fill the book with ruminations of love and lust, the foibles of marriage and the freedom of adultery--but happily, these are only a small percentage of the whole, ornaments rather than the centerpiece. This is a book with larger visions than that.

THE CENTER OF THOSE visions is Col. Hakim Felix Ellello*u, president-for-life of Kush, minister of defense, ch*airman of the revolutionary council, architect of his nation's already-crumbling monuments to fanatical Islamic Marxism, and lecher extraordinaire. Ellello*u continually varies his narrative between the third and the first person--"There comes a time in a man's life," he explains in the midst of crisis, "when he thinks of himself in the third person"--but never varies in his ribald, poetic, heart-driven rhetoric. Revolutionary and demagogue, seducer and saint, political puritan and sexual adventurer, he sees Kush as an extension of himself--a citadel of purity besieged by the persistent corruption of American capitalism and, worse, Western morals. He rejects it all, railing and carping in Updike's brilliant satirization of tunnel-eyed Marxist bombast, and secures his not-so-willing nation against the world by the sheer power of his will. The only problem is the drought.

To Ellello*u, the drought that brings his nation to the limits of starvation is more than a mischance of the elements or even, as one of his enemies calls it, "bad ecology." It represents a blot on the nation's soul, a demon that has to be exorcised, the work of an angry Allah demanding sacrifice. So he sacrifices. First goes the ancient king who had been his prisoner since the revolution, then an American foreign service officer who tries to bring food supplies across the border from a less doctrinaire socialist, and less impoverished, neighbor. In each case Ellello*u shows a flair for the dramatic--beheading the first, incinerating the second atop a huge pyramid of offered breakfast cereal and potato chips--but little sense of the inevitable. It is only after the drought worsens that Ellello*u begins to suspect that he might be the desired sacrifice.

And so he wanders out into the desert, accompanied by the dearest of his four wives, to begin a search for the oracle that, he is told, will tell him how to end the drought. It seems cornballed at first, simple adventurism, but Updike is never simple. Through Ellello*u. Updike sings an elegy to the open spaces he seems to have just now found: the vast blue sky of Africa, and the rolling plains of the 1950s America in which both Ellellou and Updike attended college. This makes the most beautiful part of the book, striking in its images and complex in its construction; Updike interweaves flashback and narrative to force a sad comparison between the America that believed so deeply when Ike said it was happy, and the nation that since developed out of that same era of uneasy, deluded simplicity. The narrative wanders, like Ellello*u, through a landscape of desolate beauty and frightening foreshadowings, and finally comes back to a world of bittersweet humor and fantastic conclusions. The American of the '50s, reborn in Africa, greets Ellello*u as he emerges from the desert, and each calls the other a sham. Each is right.

AS CAREFULLY AS HE has molded Ellello*u out of fiery words and fanatic ideas, Updike has created a supporting cast of splendid variety. Ellello*u's foppish political opponents, his wispy and wisely degenerate king, his seductive and bitchy and monstrous wives, all create an atmosphere of debauched craziness tempered by childlike seriousness. This aura is, in turn, scientifically punctured by the sickeningly helpful middle-Americans and mysterious vodka-guzzling Russians who emerge from the shadows to help separate the dictator from his people. Blending caricature and truth, Updike thus manages a type of satire that helps heal over with humor what it has just incised--a satisfying trick.

That is, in fact, the best thing that can be said of this book--it satisfies in a way that few of Updike's recent works, though so precisely tooled, can manage. By taking on the wide spaces, forgetting the parking lots and PTAs and roadside motel rooms, he opens up new canyons where his imagination can wander, and reflect.

There is a real sense of fatalism here, born of mature confidence; Updike, unafraid in his writing, seems like the narrator who claims that, "Ellello*u's body and career carriedme here, there, and I never knew why, but submitted." Updike obviously knows where he is going, and the reader would be wise to submit; this journey is worth the price.