ASHINGTON
In the last week the prospects for peace between Israelis and Palestinians appeared to be improving. The Palestinians approved Mahmoud Abbas as their first-ever prime minister, and he declared that terrorism threatened to destroy the Palestinian cause — language one never heard from Yasir Arafat. Prime Minister Ariel Sharon of Israel reiterated his understanding that it would take painful concessions by Israel to achieve peace, including a willingness to part with areas central to Jewish history like Bethlehem, Shilo and Beit El. And Secretary of State Colin Powell is on his way to Jerusalem to promote President Bush's "road map" toward a peacefully coexisting Israel and Palestine.

But these hopeful signs were accompanied by a suicide bombing in Tel Aviv and an Israeli incursion in Gaza, which yet again left noncombatants dead on both sides. Then Mr. Abbas was stymied by Mr. Arafat and other Palestinian leaders over his plans to reorganize the Palestinian security services. And aides to Mr. Sharon said Israel was unlikely to commit to the road map until after he meets with President Bush in a few weeks.

Are we watching yet another brief moment of opportunity undone by Palestinian terrorism and Israeli reprisal? Perhaps not — we are at a promising stage because the interests of the Israelis and Palestinians have greatly converged. But everyone involved must recognize what is possible and what is not. These shared concerns of the leaders on both sides only involve stopping the current Intifadah. We must focus on changes in the near-term reality, not a lasting peace that would require concessions neither side can make now.

Mr. Sharon knows that Israel's economic woes cannot be overcome so long as the daily struggle with the Palestinians goes on. Nor can the Israeli Defense Force stay in the Palestinian cities of the West Bank indefinitely. It is not only that Israel's army, largely made up of reserves, is being sapped in terms of manpower and morale, but also that the Palestinians' hostility toward Israel will continue as long as they feel the cities are under siege.

For his part, Mr. Abbas knows that the war is a disaster for the Palestinians. Nearly two-thirds of those in the West Bank and Gaza are living below the poverty line. More than 2,000 have been killed; 30,000 more have been wounded. Some 580 schools have closed, as students cannot get to them. And polls of Palestinians now show a decisive majority favor an end to the violence.

Thus neither prime minister is focused on the endgame of peacemaking right now. Mr. Abbas has no authority to make concessions on issues like the control of Jerusalem, borders and refugees. To gain credibility on tackling these core questions, he has to show that he can reform the Palestinian Authority and reduce Israeli control of Palestinian lives. Ariel Sharon, for his part, won't consider addressing the major issues until he knows that he has a partner who will truly dismantle all the terrorism networks in the Palestinian areas. None of this will happen overnight.

From this standpoint, the road map makes sense. It speaks of three phases to peace, and does not immediately get to trying to resolve the issues of Jerusalem, borders and refugees until the third phase. Its weakness, however, is that it offers an illusion of specificity, with dozens of paragraphs of obligations for each side, but without any clear way to set in motion the actions Palestinians and Israelis must take.

Moreover, the absence of clear measuring sticks for judging performance will leave each side in a position to claim it has done what was required, no matter the reality. For example, the Palestinians are supposed to make arrests and dismantle terrorist groups. But how many people should be arrested, and who are the key targets? What does the essential terrorist network consist of, and does it include the Dawa — the social support structure of the terrorist group Hamas?

On the Israeli side, what is the real number of illegal settler outposts? Israel is supposed to withdraw to its defense force positions of September 2000, but where exactly were they?

Without clear understandings between the Israelis and the Palestinians now, the road map is likely to go the way of the Mitchell Report and the Tenet plan before it. However, it is not just the road map that requires these specific understandings. There also needs to be a concrete plan on changing the immediate situation. No Israeli prime minister — certainly not Ariel Sharon — is going to relax Israeli controls on the Palestinians if it might lead to a new wave of suicide bombings. And the first Palestinian prime minister is not going to be able to sustain difficult steps against groups like Hamas, Islamic Jihad and Al Aksa Martyrs Brigades of Fatah if he cannot show his people that they are going to be able resume normal life without border closings, sieges of cities, and Israeli checkpoints separating their towns and villages.

The two sides need to be clear on what each is going to do, where it is going to do it, how it is going to do it, and when it is going to do it. Can they come to an agreement on their own? I doubt it. From my long experience dealing with the two sides, I know that the potential for using the same language to mean different things existed even in the best of times of dialogue and cooperation. Now, in a very hostile environment, the potential to talk past each other and inadvertently create profound misunderstandings is even greater. It is already visible in the debate over "confronting" Hamas — with Palestinians feeling this means persuasion, the Israelis that it means physical destruction.

Israeli expectations must be reconciled with Palestinian capacities — and that will happen only with American help. Mr. Powell has the best chance of success this weekend if he puts his emphasis on near-term specifics. His success at getting the two sides to agree on what to do now will determine whether the road map is a genuine path toward peace or yet another Middle Eastern cul-de-sac.

Dennis Ross, envoy to the Middle East in the Clinton Administration, is director of the Washington Institute for Near East Policy.