The passing of Yasser Arafat -- now living out his last moments in Paris -- will not open up new opportunities for multilateral negotiating. It's too late for that: The new order for the Israeli-Palestinian feud is unilateral engineering.

Today, Prime Minister Tony Blair is scheduled to arrive in the States to tell President George W. Bush, as he has told Britons, that "the need to revitalize the peace process is the single most pressing challenge in our world today." Blair will argue that the departure of Arafat -- whom few regarded as a "partner for peace" -- offers a fresh moment for a new round of peace talks.

Blair, of course, is Bush's stalwart ally in the Iraq war. And, like world opinion overall, British public opinion is substantially pro-Palestinian. So Blair, routinely derided in the British media as "Bush's poodle," is eager to show that he has influence on the president in regard to the Israel-Palestine issue. After all, he faces a re-election battle of his own. Most likely, Blair will seek to reinvigorate "the Quartet" -- the United States, the United Nations, the European Union, Russia -- as an instrument of multilateral mediation.

But the Israelis mistrust the non-American three-fourths of that Quartet. And so do many in the U.S. government -- and probably Bush himself.

In the meantime, the Jerusalem government of Prime Minister Ariel Sharon believes it has found the optimum available solution for the Palestinian problem. Call it the Great Wall of Israel. Every day now, construction crews are building a huge physical barrier between Jews and Arabs. According to current plans, the Wall will put perhaps a tenth of the West Bank territory -- and possibly 100,000 Palestinians -- on the Israeli side, in what will likely amount to a permanent annexation of that land.

But crucially, the Wall, when completed, will put more than 2 million Palestinians outside the fence, sealed off, it's hoped, from further acts of violence against the Jewish state. Of course, security is never that easy. In the West Bank, and also in the Gaza Strip, Israelis will continue to exercise military control, mostly to prevent the infiltration of weapons. In effect, the West Bank and Gaza will be two disconnected territories for some 3 million Palestinians, surrounded by Israeli concrete and barbed wire.

Palestinians and their supporters, not surprisingly, are outraged. The Israeli answer is that Arafat had a chance to gain at least the semblance of a Palestinian state four years ago, during the waning days of the Clinton administration. But now it's too late: the Sharon government is changing the facts on the ground, permanently. So there's nothing to negotiate.

Will the Wall work? Daniel Pipes, of the neoconservative Middle East Forum, predicted on Fox News that the Palestinian areas would dissolve into "chaos and anarchy" and that "two different warlords" might end up in charge of the two zones. But will it be possible to insulate Israel from such violence? Martin Van Creveld, author of the new book "Defending Israel: A Controversial Plan Toward Peace," advises building "a wall so high that a bird can't fly over it."

That will be difficult. Just on Saturday, Hezbollah, the guerrilla group based in Lebanon, succeeded in flying a small drone plane over Israeli territory before landing it safely back in Lebanon. Where was the Israeli air-defense system? Good question. And what might Hezbollah succeed in flying next? Better question.

The Sharon government's response will be to redouble security efforts because, it says, there is no alternative to unilateral security measures. And, with the Bush administration solidly in Sharon's corner, multilateral efforts, such as those advocated by Blair and the Quartet, will inevitably fall flat.

So Arafat's death will be an anti-climax. The era of "peace talks" is over; the era of wall-building has begun. But, as we look ahead, the question for Americans is whether it's possible to put a security wall around all the U.S. interests in the Middle East -- starting with the devastated town of Fallujah.