WASHINGTON, 8 September 2003 — Just three months ago, after President Bush held back-to-back summits on the Red Sea to promote a US-backed plan for Israeli-Palestinian peace, he discussed with reporters on Air Force One how presidents before him had worked for peace, but confidently added, “Maybe history is such that now we can achieve it.’’

The president’s comment was not an idle one, but made during an unusual 45-minute conversation that reflected his clear pleasure at the outcome of the summits.

With the sudden resignation Saturday of Palestinian Prime Minister Mahmoud Abbas, those hopes seemed in tatters. The Bush administration had invested time and money in an effort to bolster Abbas in his struggle with Palestinian leader Yasser Arafat. Some US officials say the resignation leaves the situation perilous, with little maneuvering room after a summer of missed opportunities and a shirking of responsibilities by all sides.

Indeed, the turn of events points to a central contradiction of the administration’s approach to the conflict: US officials refuse to deal with Arafat, the elected leader of the Palestinian people, and yet the success of their plan relies on a Palestinian official appointed by Arafat, who can limit his authority at any time. The Bush administration provided $20 million over the summer directly to the Palestinian Authority, in a sign of respect for Abbas, but otherwise officials have done little to try to affect Arafat’s standing among the Palestinians.

The constant shunning of Arafat by the Americans — while European officials continue to meet with him — instead has only enhanced his stature in the Palestinian territories. Abbas, widely viewed as an American and Israeli lackey, leaves office with an approval rating of just 1.8 percent.

Abbas’s resignation is likely to sharpen a debate within the administration about whether to embrace the long-standing Israeli desire to remove Arafat from power and send him into exile. Shunning Arafat while hoping a new leader would emerge had been the uncomfortable compromise reached in June 2002, when Bush called for new Palestinian leadership. Some officials had pushed for Arafat’s ouster and others had argued for continuing to work with Arafat.

It seems unlikely the administration would reverse course and begin to talk to Arafat again, although Secretary of State Colin L. Powell took the unusual step last month of calling on Arafat to support the peace process. But allowing the Israelis to exile Arafat would be a dramatic step that the administration may be hesitant to take as it deals with the continuing fallout from the war in Iraq.

White House spokesman Scott McClellan, signaling there would be no weakening of the administration’s stance against Arafat, noted in a statement Saturday: “The creation of the office of prime minister was a key turning point for the Palestinian Authority in the development of new institutions to serve all the people, not just a corrupt few tainted by terror.’’

US officials, for the moment, intend to put pressure on European and Arab leaders still in contact with Arafat to insist the next prime minister has enhanced authority and powers, a senior administration official said Saturday. “Arafat is a gigantic obstacle to progress,’’ he said. “He proved that by undermining this government. He is a great and continuing problem that the Palestinians need to deal with now.’’

The official added that the “positive side’’ of Saturday’s events is that the peace process had been stymied by the continuing Palestinian infighting. “If the net effect is to produce a Cabinet that is stronger, that is a positive step,’’ he said.

The peace plan, dubbed the “road map,’’ began with high hopes after Bush traveled to the region in early June and met first with Arab leaders and then with Abbas and Israeli Prime Minister Ariel Sharon in summits on the Red Sea.

Both Abbas and Sharon promised to fulfill their commitments under the plan, which envisioned a Palestinian state by 2005, and Bush pledged to “ride herd’’ on the process, appointing a special envoy and dispatching both Powell and National Security Adviser Condoleezza Rice to the region. A cease-fire by Palestinian militant groups was soon reached, and the Israeli military turned over parts of Gaza to Palestinian control.

But the process has broken down dramatically, especially since Abbas and Sharon traveled separately to Washington for meetings with Bush. Both men arrived with bitter complaints about inaction by the other side. Abbas said the Israelis had played a shell game with the promised removal of settlement outposts; Sharon complained that Abbas had done little during the cease-fire to crack down on militants. Yet after Bush held news conferences with both men, it was unclear whether he or other US officials pressed either side hard to live up to their commitments.

Israeli and Palestinian officials complain that the US envoy, John Wolf, has been largely silent, never fulfilling the role of a public nag that would keep the focus on what each side needed to do next. US officials counter that that was never supposed to be his role. They say he has given each side a precise list of how each could fulfill the terms of the road map, but his work will not succeed if neither side has the will or the capacity to live up to its end of the bargain.

While Abbas in part blamed the United States for his resignation, saying it “did not exert sufficient influence on Israel to implement its commitments in the road map to push the peace process forward,’’ US officials likewise have been disappointed in his tenure. They feel he failed to take advantage of the cease-fire to take even incremental steps against Palestinian terror groups and missed numerous opportunities to strengthen himself against Arafat.

In addition to Abbas’s resignation, both Sharon and Bush have also been weakened since the June summits, raising doubts about whether either can or will risk political capital on the road map. Bush’s approval rating is slumping over the economy and doubts about his handling of the Iraq war, while Sharon is plagued by a corruption investigation involving how he raised money for his 1999 campaign to win the Likud leadership.