In 1938 the Roosevelt administration suggested that Jews seeking a homeland might settle in Alaska . It’s a remarkably boneheaded idea, but Michael Chabon takes it up with gleeful intelligence in The Yiddish Policemen’s Union (HarperCollins). The novel envisions a 20th century in which the Jews are driven from Palestine in 1948 and forced to a protected zone around the city of Sitka, on an island south of Juneau . They remain the dispossessed and the exiled, and it is from their beleaguered ranks that the darkly secretive terrorists of our own time are drawn. This sounds grim, but the book is also grand fun, in a Job-meets–Rodney Dangerfield kind of way. Chabon is part of a postboomer generation of writers who are fascinated by genre fiction, by comic books, crime, fantasy, and sci-fi. The Yiddish Policemen’s Union is written in the noir tradition, with booze, cigarettes, sex, and a mysterious shooting in a fleabag hotel. It features one of the great losers of contemporary American literature, Detective Meyer Landsman, abandoned, reviled, childless, alcoholic. He also happens to be intuitive and tenacious, and he follows the hotel shooting all the way to the center of a globe-size plot. The texture of the book, its northern gloom, its smell of her-ring and salt air, and its metric hop (Chabon brilliantly renders the feel of the Yiddish his characters speak) are part of its enormous pleasures. The other part is a subtler thing: It is Chabon’s affection, his fondness and even yearning for a people, the European Yiddish-speaking Jews, half-imagined, half-remembered, paid homage here by their re-creation at the center of a world that in reality they long ago departed.