President Bush's plan for Middle East peace hasn't been destroyed by this week's sudden surge in Israeli-Palestinian violence. But the prospects for its advance have almost certainly been heavily damaged.
If nothing else, the circular relationship of Mr. Bush, Israeli Prime Minister Ariel Sharon, and Palestinian Prime Minister Mahmoud Abbas has changed radically in the past few days.
For perhaps the first time, Bush appears genuinely frustrated by an Israeli action - the failed assassination attempt on Hamas leader Abdel Aziz Rantisi. Meanwhile, Prime Minister Abbas seems weaker, his status as an equal partner in negotiations damaged by his inability to restrain Hamas or influence his Israeli counterpart.
Wednesday's explosion on a Jerusalem bus - followed by Israel's instant and deadly response - demonstrates the difficulties of keeping the negotiations on track. Indeed, the defining moment for the Bush administration's peace effort may now be at hand.
Absent a strong intervention that convinces both parties that revenge is not in their best interest and that the hard-line elements on both sides must be controlled, the Bush road map may join a lengthy list of US mediation efforts that began well, but then....
"Without [Bush] being engaged, nothing will happen and the situation will get worse," says Hermann Eilts, a former US ambassador to Saudi Arabia and Egypt who is now a professor emeritas at Boston University.
For Abbas, Bush's message might be that the Palestinian leader should not give up, and that he needs to try to keep building a security structure which will, at some point, supplant or control Hamas and other radical Palestinian elements.
For Prime Minister Sharon, the US message might be blunter: Let Abbas have time to work. The new Palestinian prime minister has neither the power nor the inclination to confront Hamas now and start a Palestinian civil war. "My instinct says the US president is getting educated on the subtleties of how these sides provoke [each other]," says Marc Gopin, a Middle East expert at Tufts University's Fletcher School in Medford, Mass.
The latest cycle of violence began last week when Israel assassinated two Hamas members. Then, unusual coordinated attacks by Hamas and other hard-line Palestinian groups killed five Israeli soldiers.
It accelerated Tuesday when Israeli helicopter gunships wounded Hamas spokesman Rantisi and killed a bodyguard and bystander.
Then it exploded horrifically Wednesday, when a suicide bomber blew up a bus in Jerusalem, killing at least 15 and injuring at least 65.
In Washington, Bush condemned Wednesday's attack in "the strongest possible terms." He had earlier said that he was "deeply troubled" by Israel's attempt on Rantisi's life. He told reporters he did not feel the strike would help Israeli security, and that it could weaken Abbas.
"I'm concerned that the attacks will make it more difficult for Palestinian leadership to fight off terrorist attacks," said Bush.
Every US president in recent times has reached a point where his preconceived notions about the dynamics of the Middle East are changed by reality. For President Clinton, this point probably came when Yasser Arafat rejected a peace deal that the US leader thought was the best the Palestinians were likely to see for years.
For the first President Bush, it could well have been a nasty dispute over perceived Israeli misuse of US housing-loan guarantees to build settlements in the occupied territories.
Even President Carter, the architect of the Camp David accords, grew disillusioned before he left office about the lack of continued progress toward peace in the region. The younger Bush came into office as a staunch supporter of Israel, and most Israeli policies. He has called Sharon a "man of peace."
But if the Bush road map for peace is ever to be implemented, the US will have to lean on Israelis, as well as Palestinians, to carry out some of its more difficult aspects. To some extent, that has already occurred. If it was not for US pressure, Sharon would have been unlikely to agree to the road map in the first place.
In the time since the summit in Jordan between Bush and the Israeli and Palestinian leaders, further strains may have developed between Bush and Sharon. The US vision of the current peace process has included allowing Abbas time to consolidate control over hard-liners and establish himself as a true alternative to Mr. Arafat.
Yet as the assassination attempt against Rantisi made clear, Sharon believes that if Abbas does not confront Hamas and other rejectionist groups directly, the Israelis will do it for him. The security of Israel as a nation demands such action, according to Sharon. In this belief he is supported by most of Israeli society. Sharon "ironically may feel more pressure to respond [to attacks] due to the fact that he has said 'yes' to the road map," says Jim Walsh, an expert at Harvard University's John F. Kennedy School of Government.
The current cycle of violence was predictable, say experts. Something similar happened in the wake of the 1993 Oslo accords. "Once you make one step forward, there are going to be extremists on either side to pull you back," says Mr. Walsh.
It's possible that nothing can now prevent the peace process from stalling. But if Bush hammers away at both sides, it is at least possible that the current crisis of violence won't become a political crisis, say some experts. "Now it's time for leadership," says Marc Gopin of the Fletcher School. "You build with a clear vision of the goal and what steps need to be taken to get to that goal."