It’s going to be illuminating to see in the weeks ahead how the Tehran conference of Holocaust denial ripples through the political debate. Over the weekend the Wall Street Journal issued an important dispatch by its columnist Bret Stephens on how what he called “global polite society” has been “blazing its own merry trail toward this occasion for decades.” He talked about the reckless comparisons between the actions of Israel and those of the Nazis. He quotes the comparisons of the fight in Jenin to the Warsaw Ghetto.

Mr. Stephens quotes New York University’s Tony Judt, writing in the New York Review of Books, as calling Zionism “the dogma of intolerant, belligerent, self-righteous, God-fearing irridentists.” And a British parliamentarian, Gerald Kaufman, as saying: “If the United States is keen to invade countries that disrupt international standards of order, should not Israel, for example, be considered as a candidate.” And Prime Minister Rocard, the former leader of France, as asserting that Israel was “an entity that continues to pose a threat to its neighbors until today.”

The Journal’s columnist also mentions Professors Stephen Walt and John Mearsheimer, whose critique of the Jewish lobby and protestations not to be anti-Semitic echo those of David Duke, who made an appearance at the Tehran conference. “Would they exonerate him of being an anti-Semite?” Mr. Stephens asks. “In fact,” he goes on to conclude, “anti-Zionism has become for many anti-Semites a cloak of political convenience.” We would suggest that it’s one of the most important things to comprehend about politics today.

In September of 1982, back during Israel’s first war in Lebanon, Commentary magazine published an article called “J’Accuse.” Its author, Norman Podhoretz, sketched a logic for use in determining whether attacks on Israel, then erupting in the context of the Lebanon war, were anti-Semitic. His method, which caused a surge of understanding through the Jewish community and beyond, had to do with seeking to gain a sense of the criticism’s proportionality.

Mr. Podhoretz concluded by noting that in the broadside from which he had borrowed the title of Commentary essay, Emile Zola charged that “the persecutors of Dreyfus were using anti-Semitism as a screen for their reactionary political designs.” The new anti-Semitic attacks on Israel, Mr. Podhoretz concluded, were also a cover — this time “for a loss of American nerve. … for acquiescence in terrorism. … for the appeasement of totalitarianism.”

He accused those who had crossed the line “not merely of anti-Semitism but of the broader sin of faithlessness to the interests of the United States and indeed to the values of Western civilization as a whole.” And that, we predict, is what is going to become clear, in the weeks after the Tehran conference, in respect of the attacks on Israel and the Jews. It is no coincidence that this is happening as we enter the most difficult phase of a new war in which Israel and America are being targeted by a broad front of enemies animated by the age-old hostility.