The calamity that turned the nation toward military confrontation is also revealing the character of its people, both collectively and individually. From the overwhelming majority, not only in America’s greatest city but everywhere, we have seen evidence of altruism, nobility and tolerance. These qualities encourage hope that we will also summon the patience and judgment necessary to prevail against an elusive enemy.

From a few notable individuals, however, we have seen opportunism, incitement and ugliness, sometimes blatant and even violent in tone, sometimes more subtle. While the examples may seem marginal, they represent themes that are potentially divisive and damaging.

The most notorious offenders of decency in the aftermath of the assault on America were religious-right leaders Jerry Falwell and Pat Robertson. Ordinarily somewhat hostile and competitive toward each other, this pious pair found quick agreement about the underlying cause of the attacks on New York and Washington: God had withdrawn divine protection from the United States in retribution for the freedom afforded to homosexuals, civil libertarians and feminists, and thus had permitted “the enemies of America to give us probably what we deserve.”

Said Mr. Robertson, “Jerry, that’s my feeling.”

Just so nobody could misunderstand his meaning, Mr. Falwell berated “the pagans and the abortionists and the feminists and the gays and the lesbians who are actively trying to make that an alternative lifestyle, the [American Civil Liberties Union], People for the American Way …. I point the finger in their face and say, ‘You helped this happen.’”

Informed that their remarks had repelled even the most conservative figures in the White House, they reverted to damage control. Mr. Falwell falsely claimed that he had been quoted “out of context.” Then he apologized, rather feebly, but did not withdraw those statements, which he described as too theologically subtle for comprehension by secular Americans.

Mr. Robertson suddenly pretended to be among those who didn’t comprehend Mr. Falwell’s meaning. He joined in the chorus of condemnation, saying he had “not fully understood” his guest’s “severe and harsh” comments.

It is worth pointing out here that the Mayor of New York, whose leadership has been so admirable, currently lives as the roommate of a gay couple—and that one of the heroic passengers who resisted the hijackers on the plane that crashed in Pennsylvania was a gay rugby player named Mark Bingham.

Messrs. Falwell and Robertson were not the only “conservatives” who vented hostile emotion last week. Under the banner of National Review magazine, commentator Ann Coulter called on Sept. 13 for the U.S. to “invade their countries, kill their leaders and convert them to Christianity.” Which countries she did not specify, but her essay reflected the widespread rightist desire for an instantaneous and indiscriminate response, up to and including the use of tactical nuclear weapons. Such demented rhetoric undermines America and our allies as they seek diplomatic and military support for a difficult, delicate and potentially very costly campaign.

While some personalities on the right have indulged in ideological scapegoating, certain figures on the left have behaved similarly, if not as grossly. Although they ritualistically denounce the hideous crime perpetrated on Sept. 11, they simultaneously seize this chance to promote their own project of undermining U.S. support for Israel.

Their contribution to the current debate is to suggest, as professors Noam Chomsky and Edward Said and writer Christopher Hitchens have done in recent days, that the attacks must be “understood” as the reaction of the world’s dispossessed to the depredations of an imperial America and its Zionist client state. More broadly, these same commentators and others insist that the savagery of the bin Laden group and its comrades is rooted in the poverty and misery that arise from globalization.

For thoughtful Americans concerned about the past excesses of our own government and of Israel, these are seductive arguments. They are also mistaken, at best, and sinister at worst.

As a general proposition, it is true that terrorist groups have exploited real grievances over the years, from the Irish Republican Army and the early Zionist movement to the Palestine Liberation Organization. But in the conflict that we are about to enter, the enemy is not an oppressed nationalist group with negotiable goals. It is instead a reactionary international movement with aspirations to destroy Western democracy. Its ideology is medieval, opposed to progress in every sense. Its policy is the brutal repression of women, labor, peasants and any dissenting social force. Its model is its own version of “the Caliphate,” meaning an imperial perversion of Islam that puts infidels to the sword. Its bloodlust would not be satisfied by a just settlement between Israelis and Palestinians.

That barbarism is what needs to be understood—and resisted with force.