The Middle East peace process has been here before: at a crossroads where terrorist violence could explode hopes for peace. Nothing would make the terrorists happier than to precipitate that explosion.
The alternative, as always, is to use this latest tragedy - suicide bombings in a crowded Jerusalem marketplace - as an incentive to get on with negotiations. A negotiated settlement of the differences between Israel and the Palestinians of the West Bank and Gaza remains the only path away from recurrent violence and war.
Progress along that path ground to a halt last March, when Palestinians protested the construction of new Israeli housing at an East Jerusalem site. Only recently have there been signs of hope, with useful meetings between Palestinian and Israeli high officials, and an Israeli move to suspend the permit for yet another building project in East Jerusalem.
American mediator Dennis Ross had been on his way to the region to help revive the peace process - a much needed affirmation that the US remains engaged in that process under Secretary of State Madeleine Albright.
For now, however, all plans have been shelved by the bombings, which killed at least 13 people other than the bombers and wounded more than 150. In the immediate aftermath, Israel's government has demanded stronger antiterrorism measures by Yasser Arafat's Palestinian Authority, and is likely to take strong police action itself against Hamas and Islamic Jihad, the organizations that have spawned suicide bombers.
For his part, Mr. Arafat can and should do more to root out the extremist cells stockpiling explosives for such missions. He, too, will order sweeps and arrests. An immediate danger is armed confrontation between Israeli and Palestinian security forces, which should be operating in concert against the terrorist threat, not at odds with each other.
But the current dynamics of the situation invite conflict and misunderstanding. In the absence of regular talks, the two sides have receded into distrust. Each side has internal problems as well. Arafat is operating under both logistical and political constraints. His security resources are limited, and the politics enveloping the Palestinian Authority have never been more tense. On July 29, a panel of Palestinian lawmakers urged legal action against top Arafat aides, charging them with corruption. The legislators' report confirms the scant regard many Palestinians have for Authority officials, who are scorned for shows of privilege.
Arafat has never had a greater need to show that the peace process he champions can move forward - or less ability, politically, to launch the kind of massive security crackdown Israel's government wants.
Israeli Prime Minister Benjamin Netanyahu remains on shaky political ground himself. The bombings will heighten calls from his right wing to junk the whole Oslo process. Netanyahu could seize on the present crisis to do just that. But he, too, is heavily invested in the process, having made a crucial decision earlier this year to give the Palestinians control of all but a tiny part of the key West Bank town of Hebron. That was to have thrust the peace talks into gear - except that the Jerusalem building controversy, and frequent outbreaks of violence among the Palestinians, jammed the gears.
Can the peace plan still be salvaged? It has always demanded supreme patience and goodwill, with its gradual turnover of authority and territory. Those qualities ultimately have to be found in the region itself, but they need extraordinary bolstering from outside. The US role has never been more critical.