When US envoy Anthony Zinni tried to broker an Israeli-Palestinian cease-fire late last year, he failed because he seemed to lack the leeway to pressure Israeli Prime Minister Ariel Sharon, say diplomats here.
As he returns this week for another attempt, success will hinge on whether he can push the Israelis - and not just the Palestinians - toward compromise.
"During this mission, to salvage the situation, he needs to talk turkey with both sides," observes a US official who spoke on condition of anonymity.
Over the weekend, Mr. Sharon indicated new flexibility toward a cease-fire, saying he would no longer insist that seven days of absolute quiet precede any interim confidence building steps.
The major prompt for the Zinni trip is that the first 10 days of March have been the worst period of violence here in the past 18 months. On Friday, Israeli forces killed 39 Palestinians, mainly during sweeping incursions into refugee camps in the West Bank. Six Israelis also died, including five teenage military trainees who were killed after a Palestinian fighter crept into their settlement in the Gaza Strip.
Signs of conciliation are no surprise in advance of high-profile US intervention, but the Israeli leader may not have his eye only on Mr. Zinni. Vice President Dick Cheney, now on a Middle East tour intended to rally support for a possible US attempt to overthrow Iraqi President Saddam Hussein, is expected in Israel March 18.
"For Sharon, what is going on with the Palestinians is bad and bloody," says a European diplomat who also requested anonymity, "but Iraq and Iran are strategic." The diplomat's idea is that Sharon will do what he can to encourage any US plan to defang states in the region that pose a major military threat to Israel.
Statements last week by President Bush and Secretary of State Colin Powell suggest that the US is toning down its support for Mr. Sharon's hardline tactics in countering the Palestinians' resistance against Israeli occupation, but the substance of any shift will be measured when Zinni arrives, perhaps by the end of the week.
The retired general is inserting himself into an increasingly deadly struggle.
For two Saturdays in a row, Palestinian suicide bombers have marked the end of the Jewish sabbath by detonating their explosives in central Jerusalem. The two attacks alone took 21 Israeli lives.
But both attacks took place in the context of massive Israeli incursions into Palestinian refugee camps. In operations lasting several days as a time, Israeli forces have gone house-to-house in several densely populated camps, killing scores of Palestinian fighters and civilians.
The level of violence feels to some like a turning point. The Israeli daily Ha'aretz editorialized yesterday that Israelis and Palestinians may have hit the "point of attrition at which an intitial compromise can be forged."
Mohammed Rashid, a top adviser to Palestinian Authority President Yasser Arafat, says the two sides "are reaching more political and psychological balance to sit down and deal."
"It's clear today that the roots of the problem are political and the discussions should be political, not only about security," Mr. Rashid says.
"I think that's exaggerated," counters Zalman Shoval, an adviser to Sharon and a former Israeli ambassador to the US. "There is absolutely no feeling that we should go in the direction of what Arafat wants to achieve."
No matter what Sharon himself might be inclined to do, he must contend with a largely hawkish Cabinet that mostly favors sterner military action against the Palestinians, not moves toward conciliation.
The contrast between the views of Shoval and Rashid illustrates the core question Zinni will face: whether it is possible to try to pacify the two sides on Israeli terms - by discussing security alone - or whether it is necessary to address the Palestinians' insistence that the process of reaching a cease-fire includes political components, such as a timeline for the creation of a Palestinian state.
In his earlier attempts to reach a cease-fire, which began last November, Zinni appeared to diplomats he encountered to concentrate almost exclusively on pressuring Mr. Arafat to enforce his cease-fire commitments. "[Zinni] had limited parameters; I won't say he had no discretion," says the European diplomat.
His observation is backed up by two other diplomats familiar with Zinni's earlier missions. What is unstated is the source of those parameters: presumably, officials in the Bush administration.
But there are indications that the administration is rethinking its backing for the Israeli leader. Such a reassessment might provide Zinni with more legroom to deal with the Israelis.
Sharon seems to have alarmed the US by saying aloud that the Palestinians must be "hit" or "beaten" until they call for a cease-fire, and then following up those words with continuous, large-scale military operations. Secretary Powell said last week that he didn't know where such a strategy might lead.
Mr. Bush seconded that criticism Thursday by saying of Sharon: "I think he recognizes that you can't achieve peace by allowing violence to escalate or causing violence to escalate."
These comments may be driven by concern over the scale of violence now taking place between the Israelis and the Palestinians and how that might affect other US policy goals in the Middle East, such as the move against Iraq.
But it may be that people in Washington, says the US official, "see that the Israeli body politic sees itself on a road to nowhere ... and that makes it easier for them to take a new tone themselves."