In the 1979 novel “The Ghost Writer,” a young writer very much like Philip Roth has begun writing the stories that will scandalize his fellow American Jews. Accused of giving ammunition to the anti-Semites, Nathan Zuckerman dismisses the fears of his parents’ generation, famously saying that the only real violence being done to the Jews of America is in the offices of plastic surgeons. He also imagines that Anne Frank has somehow survived the war only to enter into an affair with Zuckerman that will forever forestall charges that he is a “self-hating Jew.”

In the 2004 novel “The Plot Against America,” a young boy very much like Philip Roth — in fact, his name is Philip Roth — grows up in the nightmare that Zuckerman had tried to deny. Like the Anne Frank episode, the nightmare takes the form of an alternate history, in which the isolationist, white supremacist, pro-German Charles Lindbergh defeats Franklin Roosevelt in the 1940 election. Lindbergh almost immediately signs nonaggression pacts with the Nazis and Japan, and America basks in the relief that its sons will not have to go off to fight a foreign war. For American Jews like the Roths of Newark, N.J., Lindbergh’s nativism is not only an abandonment of the Jews of Europe but an ominous rejection of their sense of Americanism. “It can’t happen here?” It can, and it will.

Roth’s empathy for a previous generation’s insecurities is not the only inversion in his remarkable new novel. In book after book, the typical Roth hero is the assimilated Jew eager to break free of the narrow confines of his parents’ ethnicity. In his latest, the assimilationists are the villains, and the heroes are the Jews who believe their teeming urban neighborhoods are no less “American” than the non-Jewish “heartland.”

In his early stories, a Roth character might ridicule a rabbi trying to keep his young charges from merging — and mating — with non-Jewish America. In “The Plot,” the most morally bankrupt character is a pompous Newark rabbi Roth calls Lionel Bengelsdorf. The rabbi endorses Lindbergh and collaborates with the president in a plan to relocate Jews from the cities to the countryside, where they might “enrich their Americanness over the generations.” By taking the Jew out of the ghetto, they hope to take the ghetto out of the Jew.

That ghetto is Newark, namely the Weequahic neighborhood of “tree-lined streets” and “framed wooden houses with red-brick stoops,” where fathers are self-employed as plumbers and electricians or are “foot-soldier salesmen” like Herman Roth. The mothers are not the punchlines to Jewish jokes but tireless housewives who perform “each day in methodical opposition to life’s unruly flux.” Historical figures are brought to life, such as Newark’s first and only Jewish mayor, Meyer Ellenstein, the German refugee and civil rights leader Rabbi Joachim Prinz, and the gangster Longy Zwillman.

By recreating the Newark of his youth, the 71-year-old Roth pulls off the ultimate inversion. The novelist who has vigorously denied the autobiographical nature of his novels — novels that feature Roth-like writers struggling with fame, infamy and their libidos — now depicts his real family in a setting drawn from the fabulist edges of genre fiction.

The result, however, is more than a literary game. By carefully recreating his boyhood on Summit Avenue, and at the same time imagining an America in which the Nazi foreign minister von Ribbentrop is feted at a White House dinner, Roth manages to make even more precious the idea of America and the incredible promise the country made — and made good on — for generations of immigrants and their children.

His Lindbergh is not a raving anti-Semite, but a plain-talking populist whose declared aim is “to preserve American democracy by preventing America from taking part in another world war.” Indeed, the aviator-hero’s message sounds so appealing that you begin to ponder why America ever did enter the war. We take for granted the accomplishments of the “Greatest Generation,” forgetting how Roosevelt — a saint to the working-class families of Roth’s Jewish Newark — had nearly to bully the country into understanding how its self-interest, intrinsic morality and revulsion toward fascism trumped the isolationists’ amoral, short-sighted strategy of appeasement. The fact that demagogues like Henry Ford, Father Charles Coughlin and Lindbergh lost the argument doesn’t mean they couldn’t have won, or won’t win again.

It’s that understanding that has made the book very much of the moment. It’s fruitless to map the protagonists and antagonists onto the current presidential campaign, as if Bush were Lindbergh, or, conversely, those who oppose the war in Iraq were isolationists. The novel is not an op-ed. (Although writing in The New York Times Book Review, Roth described George W. Bush “as a man unfit to run a hardware store, let alone a nation like this one.”) Rather, Roth is tapping into an unease on the part of many who feel that certain strands of the American fabric — woven of respect for civil liberties, the appropriate place of church and state, and a commitment to lifting the powerless — are unraveling.

For the Jewish reader, the novel is about a very specific unease about a very specific form of hatred — anti-Semitism — and especially how it shaped generations of American Jews who were, and were not, its victims. In depicting a large cast of Jewish characters, “real” and imagined, Roth strives to understand who they became as a reaction to the choices available to them. There are those, like his father, Herman, who lifted themselves out of their own parents’ immigrant poverty and social exclusion “almost entirely by virtue of a vigilant, programmatic industriousness.” And there are the ruthless businessmen, like Abe Steinheim — who built a multimillion-dollar construction business “after a major family war had put his two brothers out on the street” — who are driven by a hunger never to kowtow to the non-Jews who slight them.

Roth draws these characters with a generosity that was often missing in his earlier, angrier books (angrier about Judaism, anyway). Maybe that’s why the novel’s jacket photo is one of the few to depict Roth smiling. Posing in front of a map of Newark, he looks like a man who has achieved peace with his past.

The future, however, is another story. Roth has suggested that the book is more about the 1940s than the present, but it arrives at a cultural moment when a growing number of Jewish intellectuals have begun to worry again about what they had assumed to be the waning scourge of anti-Semitism. There are few more sobering books to read back to back than “The Plot Against America” and “Those Who Forget the Past,” Ron Rosenbaum’s collection of essays on the “new anti-Semitism.”

Children are taught history, writes Roth, as if “everything unexpected in its own time” is inevitable. And yet, “the terror of the unforeseen is what the science of history hides, turning a disaster into an epic.” By remembering the past in a new way, Roth reminds us of the uncertainty of the present.

Andrew Silow-Carroll is editor-in-chief of the New Jersey Jewish News.

“The Plot Against America” by Philip Roth (400 pages, Houghton Mifflin, $26).