WASHINGTON • Israeli and Palestinian leaders will sit down at the State Department on Thursday for the first Middle East peace talks in 20 months, with almost nothing agreed on beyond the meeting itself, and widespread skepticism in the region that peace is anywhere close at hand.

President Barack Obama has confounded skeptics by maneuvering a reluctant Palestinian Authority President Mahmoud Abbas into direct negotiations with Israeli Prime Minister Benjamin Netanyahu. The State Department session is expected to dwell on schedules and agendas, however, not the substance of the Arab-Israeli conflict.

The talks also face a ticking time bomb in the Sept. 26 expiration of Netanyahu's 10-month freeze on construction of new Jewish settlements in the West Bank. Netanyahu has declined to commit to extending the freeze; the Palestinians say they'll bolt if he doesn't.

In a fresh challenge, assailants killed four Israelis Tuesday night at the Kiryat Arba settlement near the flash point West Bank city of Hebron. An armed wing of Hamas, a militant Palestinian group that opposes the peace talks, claimed responsibility for one of the deadliest attacks on Israeli civilians in recent years.

Israel vowed retribution for the killings, which seemed designed to undercut this week's diplomacy.

Former U.S. officials, Middle East diplomats and analysts say the negotiations aren't doomed to failure but that to succeed, Obama and his team will have to intervene more forcefully than they have to date to shape the terms of the talks.

The United States, they said, will have to consider its own "bridging proposals" to span the wide gaps between Israelis and Palestinians over the status of Jerusalem, Israel's security needs, the fate of Palestinian refugees and other issues.

"We're going to know whether this process is going to succeed or fail fairly quickly," said Amjad Atallah of the Washington-based New America Foundation. "It looks bad at the outset. It can change on a dime."

There's a consensus among the Palestinian elite that coming to the peace talks without a clearer sense of what's on the table is a mistake, said Atallah, a former adviser to the Palestinian negotiating team.

In Israel, reports in the newspaper Yediot Ahronot and another Hebrew daily, Maariv, concluded that the "prevailing assessment" was that the summit in Washington would be "ceremonial and not substantive."

The meeting between Netanyahu and Abbas, hosted by Secretary of State Hillary Clinton, will be preceded today by one-on-one meetings with Obama at the White House.