Another uncertainty is when the disengagement would occur. Israeli Embassy spokesman Mark Regev insisted the withdrawal "is not connected to the American political agenda," but said the process of parliamentary approval and a referendum could well push it past the U.S. elections in November.

Sharon's plan is widely seen as driven by the need to enforce a separation between Israelis and Palestinians that will keep suicide bombers out of Israel, something three years of tough military action has failed to do.

Israeli officials also want to reduce Israeli control over a large Arab population, which poses a long-term demographic threat to Israel's remaining a democratic Jewish state. His plan, together with his support for an eventual Palestinian state, is a sharp break with his own past as a champion of settlements and the position of his own right-wing Likud Party.

"It's not just statehood for Palestinians; it's the whole idea of partition and disengagement, the unilateral withdrawal from Gaza, the evacuation of settlements. With those statements, there isn't much meaning left to the traditional Likud ideology. So these are revolutionary statements," Dennis Ross, a former U.S. peace broker, told the Senate Foreign Relations Committee recently.

Two-state solution

European, United Nations and Arab officials want to see Sharon's plan serve to restart long-stalled Israeli-Palestinian negotiations leading to the two-state solution envisioned by Bush and other world leaders.

"Whatever is suggested by the Israelis has to be part of implementing a two-state solution. It can't be something that is the endgame," said Nabil Fahmy, Egypt's ambassador to Washington. "We're not in support of unilateralism. It should be done in consultation with the Palestinians."

But Sharon and the Bush administration insist the Israelis have no Palestinian partner to negotiate with, since Arafat has shown himself to be either unwilling or unable to crack down on militants in his midst.

Instead, Israeli officials describe the Sharon plan as a "parking place" until a new Palestinian leadership emerges. Palestinians fear it will solidify Israel's hold over parts of the West Bank that they claim as part of a future state.

Even though they see no negotiations in prospect, U.S. officials don't want the plan to jeopardize any future two-state solution or the "road map" for peace endorsed last year by the United States, Europe, Russia and the United Nations.

"We still stand behind the road map, but we're open to discussing ideas that might lead to improving the situation on the ground," a U.S. official said. The Sharon plan "is being viewed in a way that would be complementary. It's not either-or."

Sharon is intent on winning Bush's endorsement, in part because he needs Bush to enlist cooperation from Europe and moderate Arab states in helping to manage the aftermath of a pullout from Gaza. Israel wants Egypt, for instance, to prevent the smuggling of cash and weapons into the Gaza Strip. Europe exerts some leverage over the Palestinians because of its heavy subsidies.

So far, however, Europe and the Arab states have not played a major role in the discussions, and Egypt's Fahmy warned that if there are no negotiations planned or under way, "we would be inclined to be negative towards it."

A number of analysts say that rather than merely trying to help shape Sharon's plan, the Bush administration needs to assume a stronger role in making sure it doesn't make things worse and at least helps set the stage for future peace talks.

Martin Indyk, ambassador to Israel under President Bill Clinton, said the United States could lead an international move to reform the Palestinian Authority or even put the Authority in "receivership," with its powers assumed by the international community and backed by NATO.