For the first time, an Israeli leader and a Palestinian leader seem genuinely committed to peace. They set a deadline for a deal by year's end.

Yet the likelihood of achieving the two-state solution they have embraced diminishes with every rocket lobbed into Israel from Hamas-controlled Gaza and with every Israeli military strike or squeeze on civilian life in Gaza.

The political and security situation is growing more desperate.

Since last Wednesday, at least 100 Palestinians and three Israelis have been killed. On Sunday, the violence spilled over to the West Bank, as Palestinians there protested Israeli attacks on Gaza.

A spokesman for the Palestinian president, Mahmoud Abbas, said contacts with Israel would be temporarily suspended.

Secretary of State Condoleezza Rice has rightly decided to go forward with a visit to the region this week. If she is to salvage the U.S.-led peace talks, she must push urgently for a cease-fire between Israel and Hamas. And she must press key Arab states to do a lot more to support Abbas and to pressure Hamas to halt the rocket attacks.

The violence is making it even harder for Abbas and Israel's prime minister, Ehud Olmert, to negotiate the core issues. Right-wing members of Olmert's government have threatened to bring down his coalition if he attempts to negotiate the sacrosanct issue of Jerusalem.

Many Israelis who do support negotiations look at Gaza - from which Israeli forces withdrew in 2005 - and legitimately ask how Israel can surrender control of the West Bank under current conditions. Abbas' security forces are weak and show little interest in, or capability of, disarming and detaining militants there.

Israel must protect its people, but a sustained ground assault on Gaza could ensnare the army indefinitely. Mounting civilian casualties from Israeli strikes, and an Israeli embargo that has deepened the suffering in Gaza, only add to the desperation and Hamas' popular support.

Egypt has sought to broker a possible cease-fire. Rice also must press Egypt to get serious about increasing military cooperation with Israel and developing a plan to stop Hamas from smuggling weapons and supplies into Gaza. Other Arab states, like Saudi Arabia, which for years urged President Bush to get involved, and Qatar, which provides some Hamas funding, also need to exert their influence.

We have been told again and again that Rice considers a peace agreement her legacy. Time, and good will, is running out.