Over the years, Ariel Dorfman -- Chilean expatriate and American writer, refugee from Pinochet's death squads and professor at Duke University -- has written movingly and often brilliantly of the cultural dislocations and political fractures of his dual heritage. Poet, playwright (''Death and the Maiden'') and essayist, Dorfman has, in an impressive body of work, done justice to the two languages that have battled for his voice and the two countries that claim his allegiance. He has written of torture and suffering, of cultural imperialism (''How to Read Donald Duck,'' with Armand Mattelart) and freedom of the press, of exile and rediscovery (most memorably in his recent autobiography, ''Heading South, Looking North''). In ''The Nanny and the Iceberg,'' his sixth novel, Dorfman reflects some of these concerns in the story of a callow 23-year-old Chilean exile in New York, Gabriel McKenzie, returning to a homeland recovering from dictatorship, a land obsessed with sex, politics and cultural identity.
The novel, except for a coda, takes the form of a long suicide note, e-mailed in installments by Gabriel to an American girlfriend, Janice. When Gabriel and his radical mother, Milagros, fled to America in the wake of the Pinochet coup, his father, Cristobal McKenzie, an expert at tracking down runaway boys, stayed behind. Cristobal is a larger-than-life Latin lover; he makes a bet with his best friend, Pablo Baron, that he will have intercourse with a woman every day of his life until his 50th birthday. Cristobal, in his wife's words, ''swore to live only for that moment when you copulate''; his axiom is that he exists because he fornicates.
Cristobal manages to maintain his daily dose of sex, finding partners at wakes and even among the nurses in the maternity ward where his wife delivers Gabriel. But Cristobal's prodigious carnality is the cause of his son's impotence: his father was there ahead of him every time he tried, Gabriel writes, ''as if his organ were in her before mine could even begin to rise up.''
Gabriel grows up in America under the looming shadow of his mother's idol, Che Guevara -- the revolutionary, now reduced to a poster above his bed, whose death brought his parents together -- waiting for the restoration of democracy in Chile so that he can seek amatory advice from his father. Soon after his return he too makes a vow, ''that I would only make love to a woman who had not tasted the fruits of my father's tongue.'' This leads him to pursue the beautiful teen-age daughter of Pablo Baron, Amanda Camila, the only female he is sure hasn't fallen to his father.