The horrendous bombings in Jerusalem last week must be making President Bush queasy about promoting new peace efforts in the Middle East. He has put off a speech laying out his long-awaited peace plan. His team has started quarreling again over its details.

That speech is still worth giving, but only on one condition: if it offers Israelis and Palestinians a strategy to escape from their vicious cycle of rage and revenge.

Cynics will argue that no such strategy is plausible. On the Palestinian side, Hamas and other terrorist groups have pledged to continue the bombing. Palestinian leaders blew the chance to negotiate a peace in 2000 and opted for violence. They have lost credibility with Israel and their own people.

Their mistakes have played into the hands of the hawkish Israeli Prime Minister Ariel Sharon. In fact they got him elected. Sharon doesn’t believe full peace is possible and is committed to keeping control of the West Bank and Gaza.

But the past week’s horrors underline just why a U.S. plan is the only hope for both Palestinians and Israelis. No matter how repelled one is by the Jerusalem carnage, the facts are these:

Israel’s incursions into the West Bank haven’t stopped the terrorists. Nor will a fence separating the West Bank and Israel. Moreover, 200,000 Jewish settlers and the soldiers protecting them will remain on the West Bank side of the fence.

The right wing’s hope of fully reoccupying the West Bank won’t solve the problem, either. Stationing large numbers of troops, once again, on the West Bank, will expose them to constant attack. Nor can Israel achieve long-term security by penning Palestinians into their towns and villages the current situation.

Unable to reach schools, hospitals, or work, Palestinians are literally going nuts. Which makes educated youths susceptible to the sick appeal of martyrdom by murder.

So what’s the U.S. formula that could change the Palestinian mindset, and provide Israelis with assurances that the change was real?

President Bush should endorse the concept of a Palestinian state, along the lines of pre-1967 Israel with border adjustments. Israel would give up most settlements; Palestinians would give up the right of refugee return to pre-1967 Israel. Final details and Jerusalem would be negotiated.

But the Palestinians would only get such a state after a number of years if they totally crushed terrorism and reformed their government in the meantime. Any backsliding, and the deal would be off.

This concept spelling out the end goal, but testing good behavior during a lead-up is the opposite of the Oslo peace process. It is also the opposite of what President Bush reportedly is set to propose.

The Oslo process called for a long interim period before final negotiations on a Palestinian state. Interim negotiations dragged, deadlines passed, more Jewish settlements went up on the West Bank in the meantime. Both sides lost trust long before final talks.

The Bush plan supposedly will suggest a “provisional” state in the bits of West Bank and Gaza territory that Palestinians now control. Palestinians will be required to stop violence and reform their government before final talks. But unless the United States spells out its preferred end goal at the beginning endorsed by Russia, the European Union, and the United Nations Palestinians won’t believe they’ll ever get a state.

If the goal were clear, however, moderate Arabs and moderate Palestinians would have leverage to press for drastic changes. Signs of what might be possible appeared last week.

For the first time, 50 Palestinians, including leading intellectuals, took out a full-page ad calling for an end to suicide bombings. Equally important, a group of respected nongovernmental leaders demanded new leadership and new elections.

Mustafa Barghouthi, the driving force behind the second initiative, told me by phone, “If the U.S. plan calls for an end of occupation on the 1967 lines this would help us bring about democratic change.”

In other words, spell out the end goal. Help Palestinian moderates to do an end run around Yasser Arafat. Require the Palestinians to prove their bona fides to Israel before they get a state. That’s the formula that could make a difference.

Anything less, and the president would be better off not giving his speech at all.