Grinning broadly, President Bush extended his arms around Palestinian Authority President Mahmoud Abbas and Israeli Prime Minister Ehud Olmert and pulled them together for a group photo yesterday on the grounds of the Naval Academy in Annapolis.

The tableau was reminiscent of a scene four years ago in the Jordanian seaside city of Aqaba, where Bush posed for pictures with Abbas and then-Prime Minister Ariel Sharon while promising to "ride herd" on the parties to reach a peace deal. That initiative quickly fell apart because of regional violence and the inability of either side to fulfill the commitments it made.

The outcome of Bush's new effort, in the twilight of his presidency, will depend greatly on the personal commitment he is willing to invest in the unfolding process, according to officials and experts on the Middle East.

"At this point, he's come to an event and he's made a speech," said Dennis Ross, the Middle East peace envoy of Presidents Bill Clinton and George H.W. Bush. "The investment will come if he starts engaging in serious diplomacy."

White House officials reject the frequent criticism that Bush has been disengaged from the Middle East peace process, while waging war in Iraq and focusing on other issues. In an Associated Press interview yesterday, Bush described himself as "very engaged, up to the moment'' in bringing Israelis, Palestinians and the representatives of more than 40 countries to Annapolis to launch his most serious attempt at Middle East peacemaking.

"I work the phones, I listen, I encourage, I have meetings. I do a lot of things," Bush said in the White House interview, shortly after returning from Annapolis.

Bernard Kouchner, the French foreign minister, said he was impressed by Bush's performance, noting that, up until the last minute, the Israelis and Palestinians could not agree on the text of a document launching the negotiations. But the two sides came together after Bush implored them in a private meeting to make one final effort to reach agreement.

"He was really important this morning . . . they found a way," Kouchner said.

The White House worked hard to provide arresting images, locating the conference in the stately Memorial Hall, an elegant room dedicated to the memory of Naval Academy graduates killed in operations or action. On the wall was a replica of the gigantic battle flag that flew over the U.S. Brig Lawrence in 1813 with the words: "Don't Give Up The Ship."

As Olmert delivered a passionate plea for the Arabs nations to accept his country, Saudi Foreign Minister Saud al-Faisal listened intently, scribbling notes and applauding tepidly when the speech was over. A few chairs away, a deputy foreign minister of Syria stared intently ahead, not looking at Olmert as he spoke.

Some experts suggested that getting 16 senior Arab officials into the same room as the Israeli leader might have been the signal achievement of yesterday's peace conference. The conference's joint paper skirted the toughest issues and essentially codified existing efforts by Olmert and Abbas to negotiate the contours of a Palestinian state by the end of 2008.

Bush's rhetoric during his opening address at the conference was also familiar, as he spoke of the battle between moderation and extremism in the Middle East, calling on the participants to support Abbas and his government as "an alternative vision for the future."

What was different yesterday, according to officials who were present and Middle East experts, was the audience. "The meeting was the message," said Martin S. Indyk of the Brookings Institution's Saban Center for Middle East Policy.

Saudi Arabia and Syria, in particular, sent representatives to Annapolis reluctantly and with skepticism. But they came, and U.S. and Israeli officials and their allies saw that as a reason for optimism, with one Israeli noting the intense dismay of Iran over Syria's presence. "There are many states around the table, of which some don't even have diplomatic relations with each other," German Foreign Minister Frank-Walter Steinmeier told reporters in Annapolis. "This in itself is already a step forward."

Palestinian leaders also seemed pleased by the large Arab turnout, which included the head of the Arab League, and delegates from Egypt, Jordan, Saudi Arabia and a dozen other countries. "We as Palestinians would never risk going alone to the negotiating table," said Nabil Abu Rudineh, Abbas's spokesman.

The last time such a large number of Arab officials appeared with their Israeli counterparts was in the 1990s. The Saudis were observers at the 1991 Madrid peace conference, which saw Israel, Syria, Lebanon, Jordan and the Palestinians take center stage in an event that led to an Israeli-Jordanian peace deal and to Israel's nearly successful negotiation with Syria over the return of the Golan Heights. The Saudis also participated in a number of follow-up meetings until 2000.

But Ross noted that the presence of so many non-Arab countries may mute the symbolism of the event, and he expressed skepticism that Bush's efforts will succeed.

"We've seen plenty of promising initial discussions regarding progress between the Israelis and Palestinians. The devil is in the details, and every process has broken down. So it's very dangerous to read too much into these processes too early," said David Rothkopf of the Carnegie Endowment for International Peace.

"We're here in year eight of the Bush administration, and this is the first serious effort they've made to address the top [issue] of the agenda of every president for the past 40 years," Rothkopf said. He added that the meeting's message might be "too little, too late."