Secretary of State Hillary Rodham Clinton met with Israeli and Palestinian leaders 11 times in three Middle Eastern cities last week, a diplomatic marathon that produced only promises that the adversaries remain committed to the latest U.S.-led peace initiative.

Clinton couldn't extract the result she needs: that the two sides put aside their differences over Jewish construction in the occupied West Bank and move on.

"All of this is complicated," Clinton acknowledged at the end of a disappointing week.

The trip's outcome was a sobering reminder of the challenge Clinton has accepted as the principal player in the Obama administration's ambitious effort to close a Mideast peace deal in one year.

Achieving a lasting peace deal has been a priority for almost every U.S. administration in the last 50 years. With President Obama focused on the U.S. economy, the peace talks offer Clinton the chance to shine with a dazzling breakthrough, but her efforts also could be derailed by disaster in the treacherous terrain of the Middle East.

As the administration ratchets up expectations, the pressure on Clinton also rises, said David Makovsky, a veteran Middle East analyst at the Washington Institute for Near East Policy.

"The klieg lights are on," he said.

Clinton took part in meetings with Israeli Prime Minister Benjamin Netanyahu and Palestinian Authority President Mahmoud Abbas in the debut round, held in Washington on Sept. 2, as well as a second round of negotiations last week in Egypt.

The fate of continued talks may rest on the outcome of the debate over the partial moratorium on settlements. Israel's 10-month restrictions limiting construction on land it seized in the 1967 Middle East War expires at the end of the month. The Palestinians want it extended as the two sides seek an agreement on the permanent borders of an independent Palestinian state, fearing more settlements will mean less land for such a state.

Last week's meetings ended amid reports of a possible three-month extension, but no agreement.

The Palestinians have said they may quit the talks without an extension, though Abbas appeared to soften that stance as the meetings concluded.

The Obama administration believes that forceful U.S. participation is the ingredient that will enable these talks to succeed where others failed.

As a former senator, lawyer and diplomat, Clinton has experience in several areas that can work in her favor. Yet there is uncertainty about whether she can step up to a tricky role that requires improvisation, grit and bluster — at precisely the right moments.

Still, she brings the skills of a seasoned politician who understands compromise, which could be used to help Netanyahu and Abbas with their foremost problem: crafting and selling a deal to their wary constituents.

"She'll be able to focus in a smart way on the larger political issues that surround the negotiations," said Robert Danin, a onetime Mideast advisor to former British Prime Minister Tony Blair.

Clinton has known Netanyahu and Abbas for decades, and their relationships have had warm and cool moments. In March, when Israeli officials embarrassed Vice President Joe Biden by announcing approvals for a new Jewish housing project in East Jerusalem, occupied in 1967, while he was there on a goodwill visit, Clinton called Netanyahu to give him a dressing-down.

But the openness of their relationship was on display this week, as Clinton and the American-educated Netanyahu poked fun at each other before meetings in the Egyptian resort city of Sharm el Sheik, and later in Jerusalem.

Clinton had taken heat from some American Jewish leaders over the last year as she demanded that Israel agree to a full halt of construction in the West Bank. Yet the former New York senator has generally maintained strong support among the Israelis and Palestinians, as well as American Jewish groups wary of Obama.

"She's the potential answer to two questions: How can the administration restore Israeli confidence, and how can it assure continued domestic support?" said Robert Malley, who was a top Mideast negotiator for President Clinton and is now with the think tank International Crisis Group in Washington.

The Palestinians have not forgotten that, as first lady in 1998, she was the Clinton administration's first public supporter of the goal of a Palestinian state.

Some foreign diplomats close to the talks are cautious in weighing which side Clinton's ascendancy is most likely to benefit, which may help her be seen as an impartial mediator by both sides.

"At different times, she's seemed to lean to different sides," said a diplomat from an Arab country who spoke on condition of anonymity.

Officials say Clinton will benefit from a series of grinding diplomatic encounters during her 20 months as secretary of State.

One was the successful effort to win support from the balky Russian and Chinese governments for a new round of United Nations sanctions against Iran. In months of phone calls and meetings, Clinton got deep into the legal language and debates on which Iranian companies should be the target of sanctions.

But administration officials acknowledge that Middle East deal-making is far different than anything Clinton has done so far.

"Nothing can prepare you completely for Israeli-Palestinian negotiations," a senior Obama administration official said.

Clinton's high-profile presence also allows Obama to delegate more of the job at a time when it is not to his advantage to be seen focused on foreign relations at the expense of the domestic economy.

Obama will step in from time to time, however, especially when it appears that the parties are so dug in that perhaps only the American president can budge them.

Clinton knows the bitter taste of failure on Mideast peacemaking because she witnessed the collapse of her husband's last-minute push in 2000, in the waning days of his administration.

But some observers say she is smart to give it a try: Americans expect their leaders to tackle the Mideast problem, even if they are cynical about the chances of success.

"There could be more questions if people thought she were missing in action," said Malley, the former negotiator.