The Sharm el-Sheikh summit today can count on sunny weather. It rains in Sharm about once a year and it’s not likely to be this Tuesday.

For Ariel Sharon’s government, though, there are distant clouds ahead – clouds forming, ironically, from the so-far promising nature of Abu-Mazen’s new Palestinian government.

This irony was foreseeable. Ever since the Sharon government’s decision, following Mr. Sharon’s electoral victory in 2000, to declare war on Yasser Arafat and render him impotent by confining him to his Ramallah headquarters, its attitude toward his presiding over the Palestinian Authority was deeply ambivalent.

On the one hand, Mr. Sharon and those around him made no secret of both their contempt for Arafat and their conviction that, all his protestations notwithstanding, he did not wish to put an end to Palestinian terror and was in fact secretly encouraging it. They sincerely believed and declared that, as long as he remained in even titular power, there was no hope for progress in Israeli-Palestinian negotiations.

Yet on the other hand, although they were never impolitic enough to say so publicly, Arafat was also a considerable convenience. No hope for progress also meant that there was no need for Israel to make major concessions to the Palestinians or to frame its policies with Palestinian positions in mind. It could concentrate on doing what Mr. Sharon wanted to do: Wipe out or drastically reduce Palestinian terror by military means and act unilaterally, by disengaging from Gaza and finishing construction of the West Bank security fence, to establish advantageous permanent borders in the absence of the bilateral peace agreement that Mr. Sharon did not believe in.

This policy succeeded brilliantly. By late 2004 Israel had militarily broken the back of the intifada, the worst political hurdles to disengagement had been cleared, the security fence was going up rapidly, and Arafat was pathetically locked up in the Muqata’a. Had he gone on languishing there for a few more years, it would have suited Mr. Sharon perfectly.

But Arafat had his last revenge. He went and died before he should have.

True, the immediate aftermath of his death has proven again how right Mr. Sharon was. Abu-Mazen’s surprising ability to firmly grasp the reins of the Palestinian Authority, conduct relatively democratic elections, and take effective steps to clamp down on the intifada’s last vestiges have shown how fraudulent were Arafat’s claims. At the very least, the countries of the world, and particularly of Europe, which went on cozening up to Arafat to the last and chiding Israel for doubting his sincerity, now owe Israel an apology. (Its chances of getting one are about as high as the chances of rain in Sharm el-Sheikh.)

Yet that’s all history. Right now Abu-Mazen is off to a good start and Israel is about to get from the world, instead of an apology, another lecture. This one will say:

“All right, you got what you wanted: No Arafat, the beginnings of a democratized Palestine, and an end to the intifada. Now it’s time for you to reciprocate. Coordinate the Gaza disengagement with the Palestinian Authority, stop building the security fence, and above all, prepare to return to the table with reasonable positions that can be a basis for negotiations, so that we can finally have the Israeli-Palestinian peace we have been dreaming of.”

It’s no secret what these “reasonable positions” are expected to be: The same positions that Mr. Sharon’s predecessor, Ehud Barak, brought to Taba in December 2000, which were a softening of the position taken by him at the end of the Camp David talks the previous summer, which were a softening of the positions taken by him when the Camp David talks began.

In other words, the same positions that Mr. Sharon denounced and ran against when he trounced Mr. Barak in the February 2001 Israeli national elections – or to put it differently, the same positions that the voters of Israel decisively rejected when they elected him.

It would indeed be a great irony if the resounding success of Mr. Sharon’s strategy should now result in its ultimate undoing.

Whether it does or not will depend for the most part, as it has so often in the past in the Israeli-Palestinian conflict, on Washington. If the Bush administration sticks by its commitments to Israel that it will not have to accept any descendants of 1948 Palestinian refugees and will be allowed to expand its 1967 borders to include “major settlement blocs” without having to cede land to a Palestinian state in return, Mr. Sharon will have no reason to regret Yasser Arafat’s death. If, on the other hand, eager to win European support in Iraq, America joins Europe in a “fair-handed approach” that expects Israel and the Palestinians to return to the chess board abandoned at Taba, Mr. Sharon may end up wishing that the late PLO chairman could be brought back to life.

When Condoleezza Rice, on her visit to Jerusalem on Sunday in advance of the Sharm el-Sheikh summit, declared that, in the age of Abu-Mazen, Israel will have to make “difficult decisions,” let us hope that this is not what she had in mind. The decisions facing Mr. Sharon at the moment are difficult enough: To push ahead with disengagement from Gaza despite the extreme disruption of Israeli life threatened by its opponents and to finish building the security fence, every kilometer of whose route is controversial. Mourning for Yasser Arafat would be a cruel thing to make him have to do in addition.

Mr. Halkin is a contributing editor of The New York Sun.