Palestinian supporters say the massive drop in terrorism that followed Israel's invasion of the West Bank is a temporary blip. That's probably true -- but only because the Palestinian Authority, Iran and neighbouring Arab nations continue to actively arm and finance local terrorist groups, a policy they will follow no matter what Israel does. U.S. President George W. Bush has repeatedly called for the region's leaders to definitively renounce terrorism. But in recent weeks, Muslim nations have actually made a point of doing just the opposite.

At last week's Organization of the Islamic Conference meeting in Malaysia, foreign ministers endorsed a resolution that condemns Israeli "state terrorism," yet exonerates Palestinian suicide bombers. The stated rationale is that groups such as Hamas are fighting "for national liberation and self-determination." But even in cases where "national liberation" is not at stake, the OIC still endorses terrorism: Another resolution exonerates Hezbollah terrorists attacking Israel from Lebanon -- even though the United Nations has certified that Israeli troops have evacuated every square inch of that country. It's small wonder the delegates could not settle on a coherent definition of terrorism. The only unifying principle in their declaration is a willingness to whitewash any attack on Israel and condemn all Israeli retaliation.

At the Beirut meeting of the Arab League two weeks ago, the Western media's focus was on Saudi Arabia's peace proposal. Yet the "Beirut declaration" similarly supported Palestinian terrorism -- which the delegates called "valiant resistance."

Elsewhere in the Islamic Middle East, the story is the same. Mullahs have twisted the principles of their religion beyond recognition in a bid to justify attacks against the Jewish state. To get around the Koranic prohibition on suicide, senior Muslim religious authorities insist Hamas and Islamic Jihad bombers are not really engaged in suicide (intihar), but rather martyrdom (istishhad). To get around the Koranic ban on killing innocents, prominent clerics have issued fatwas declaring Israel to be a head-to-toe "military society" in which even babies are soldiers. Yet in last week's OIC declaration, delegates proclaimed their "commitment to the principles and true teachings of Islam which abhor aggression, value peace, tolerance and respect as well as prohibiting the killing of innocent persons." Apparently, suicide terrorism is fully compatible with these "true teachings" -- as long as it is directed against Israel.

Muslim leaders would have us believe, in sum, that Palestinian suicide terrorists are engaged in neither suicide nor terrorism; that Jewish babies are valid "military targets" but Palestinian gunmen are not; and that using human bombs to blow up Passover Seders is consistent with the Islamic virtues of "peace, tolerance and respect." How does one begin to argue with all of this? To have a dialogue, interlocutors need some baseline quantity of shared values. It is not clear that Arabs and Westerners can satisfy that baseline any longer.

In fact, we seem to have reached such a hopeless stage that words themselves have become useless. Mr. Bush says that Arab leaders "must stand up and condemn terrorism," and that suicide bombers are murderers, "not martyrs." What strikes Americans as an aphorism comes across as arrogant blasphemy in the Arab world. According to a Jordanian Imam quoted by The New York Times: "Mr. Bush was telling us what is a martyr ... God forbids Bush from telling us who is a martyr."

The fact that we are now in a "clash of civilizations" with the Islamic world is old news. But Mr. Bush, eager to gain Arab support for an attack on Iraq, seems ignorant of how heated that clash has become in the past seven months. So long as the debate about terrorism focused on Osama bin Laden, we could find a few points of agreement with the Arab League. Morally, we were speaking different dialects, but at least it was the same basic language.

Now, however, the main front in the debate over terrorism has shifted to Israel -- whose destruction is so fervently wished for among Arabs that the plain words of the Prophet Muhammad himself are mutilated daily in order to remove any hindrance to slaughter. Against this background, two civilizations are jabbering at each other in completely alien tongues. To the extent Mr. Bush is pinning his hopes on the conceit that Yasser Arafat and other Middle Eastern dictators will renounce terrorism in exchange for an Israeli pull-out, he will fail utterly. In fact, no one even expects the Arabs to take Mr. Bush's demands seriously -- which is why the media has obsessed in recent days over Ariel Sharon's failure to comply, but ignored Arafat's.

In the present intellectual climate, the interfaith dialogue about suicide bombers Mr. Bush seeks to start is a hopeless project, and Israel has no choice but to place its trust in tanks and commandos. It would help matters if Mr. Bush understood this, rather than urging Israel to scuttle its current military campaign, which now appears to be the only half-way promising means the Jewish state has to fight terrorism.