The dirty little war of words between writer Gore Vidal and conservative columnist Norman Podhoretz appears to have gone nuclear.

Long bombarding each other with verbal abuse, Vidal and Podhoretz have now engaged in an exchange that is by all accounts ugly, burying the issues in an atomic barrage of name-calling.

Vidal, in the March 22 issue of The Nation, accused Podhoretz, who is editor of the conservative publication Commentary, and his wife Midge Decter, who runs the Committee for the Free World, of being "Israeli fifth columnists" whose loyalties are to Israel first, the United States second.

Apparently upset that Podhoretz has criticized his participation in the International PEN Congress earlier this year, Vidal described Podhoretz and wife as "more like refugees from a Woody Allen film . . ."

Noting that Decter had written in another article that Vidal "does not like his country," Vidal raised the megatonnage in his response. "Poor Midge. Of course I like my country. After all, I'm its current biographer. But now that we're really leveling with each other, I've got to tell you I don't much like your country, which is Israel."

Podhoretz, in a syndicated column printed this week in the New York Post and The Washington Post, called Vidal's short essay in The Nation's 120th anniversary edition a "blatantly anti-Semitic outburst," a "libelous accusation of treason."

"Vidal's every word is drenched in hatred of Jews," Podhoretz wrote, saying at one point that Vidal has long been "eaten with ferocious anti-Jewish feelings."

The bitterness between Vidal and the Podhoretz-Decter family apparently goes way back, and Podhoretz said yesterday that the two have known each other for 30 years, only recently engaging in verbal battles both in print and, in one case, at a California cocktail party.

Some literary scions suggest that their differences became highly public after Vidal wrote a piece in The Nation called "Some Jews and The Gays." The piece was a vitriolic response to several antigay articles in Commentary, including one by Decter called "The Boys on the Beach."

Writes Vidal: "Decter says that once faggots have 'ensconced' themselves in certain professions or arts, 'they themselves have engaged in a good deal of discriminatory practices against others. There are businesses and professions (which ones? she is congenitally short of data) in which it is less than easy for a straight, unless he makes the requisite gesture of propitiation to the homosexual in power, to get ahead.' This, of course, was Hitler's original line about the Jews: They had taken over German medicine, teaching, law, journalism. Ruthlessly, they kept out gentiles; lecherously, they demanded sexual favors."

Given this background, there were some regulars at The Nation who argued against running the latest piece because it "was not really very nice," as one put it. After it appeared, magazine insiders said, "the roof fell in" at the magazine, where letters protesting the piece were filled with anger at Vidal and at The Nation.

Hamilton Fish III, publisher of The Nation, said Vidal and the Podhoretz family "have a running battle that goes back a long way." Although some Jewish subscribers saw Vidal's March 22 essay as anti-Semitic, Fish said that "other Jewish intellectuals responded by defending the piece," which friends of Vidal said he viewed as "ironic, meant as humor, not anti-Semitism."

"I find it almost entirely subjective and tragic, really, because it prevents us from having an unfettered debate over the Middle East," Fish said.

"I think most observers regard Podhoretz's fulminations as a kind of loony right-wing intellectual fringe," Fish added.

Some, like the editors of The New Republic, not only accused Vidal of an anti-Semitic "screed," but also said when Vidal's novel "Lincoln" came out a few years ago, it received what was described as a "mildly negative" review by the Washington-based magazine.

Vidal wrote the reviewer, Thomas Keneally, that The New Republic was now in tandem with Commentary as "the Pravda of our Israeli Fifth Column" and said in his letter: "You were doubtless picked up as a reviewer who had proven his Semitophilia; and so would give me a bad review."

The New Republic editors then went on to add: "This man is ready for the funny farm."