ave you noticed how often Israel kills a Hamas activist and the victim is described by Israelis as "a senior Hamas official" or a "key operative"? This has led me to wonder: How many senior Hamas officials could there be? We're not talking about I.B.M. here. We're talking about a ragtag terrorist group. By now Israel should have killed off the entire Hamas leadership twice. Unless what is happening is something else, something I call Palestinian math: Israel kills one Hamas operative and three others volunteer to take his place, in which case what Israel is doing is actually self-destructive.

Self-destructive is, in fact, a useful term to describe Israelis and Palestinians today. "Both sides," notes the Israeli political theorist Yaron Ezrahi, "have crossed the line where self-defense has turned into self-destruction. When self-defense becomes self-destruction, only an external force can bring people back to their senses. And that force is President Bush. I think he is the only reality principle left that either side might listen to, and I hope he understands that."

You know that both sides are in self-destruction mode when you can look at their military actions and say that even if they succeeded they would be worse off. The question is not whether Israel has a right to kill senior Hamas officials. They are bad guys. The question is whether it's smart for Israelis to do it now.

The fact is, the only time Israelis have enjoyed extended periods of peace in the last decade has been when Palestinian security services disciplined their own people, in the heyday of Oslo. Unfortunately, Yasir Arafat proved unwilling to do that consistently. The whole idea of the Bush peace process is to move Mr. Arafat aside and replace him with a Palestinian prime minister, Mahmoud Abbas, who is ready to rebuild the Palestinian security services, and, in the context of an interim peace settlement, corral Hamas.

Hamas knows this. So its tactic is to goad Israel into attacks that will unravel the whole process. The smart thing for Israel to do — and it's not easy when your civilians are being murdered — is not to play into Hamas's hands. The smart thing is to say to Mr. Abbas: "How can we help you crack down on Hamas? We don't want Israel to own Hamas's demise. Palestinians have to root out this cancer within their own society. If Israelis try to do it, it will only metastasize."

Israel's supporters argue that if America can go after Osama bin Laden, Israel can go after Hamas. Of course Israel is entitled to pursue its mortal enemies, just as America does, but it cannot do it with reckless abandon, notes Mr. Ezrahi, for one reason: America will never have to live with Mr. bin Laden's children. They are far away and always will be. Israel will have to live with the Palestinians, after the war. They are right next door and always will be.

The fact is, Ariel Sharon's two years of using the Israeli Army alone to fight terrorism have not made Israelis more secure. He needs a Palestinian partner, and he has to operate and negotiate in a way that will nurture one. And the people who get that the best are Israelis. In a Yediot Ahronot poll released Friday, two-thirds of Israelis were critical of Mr. Sharon's tactic of targeted assassinations of Hamas officials and said they wanted Mr. Abbas to be given a chance to establish his authority.

It may be that Mr. Abbas can't step up to this. It may be that the Palestinians are capable only of self-destructive revenge, rather than constructive restraint and reconciliation. But surely Israel has more to gain in the long term by giving Mr. Abbas every chance to prove otherwise, and to empower him to do so, rather than killing one more Hamas "senior official," who will only be replaced by three others.

Because if the two sides cannot emerge from this dead end, then you can forget about a two-state solution, which is what both Hamas's followers and the extremist Jewish settlers want. They each want a one-state solution, in which their side will control all of Israel, the West Bank and Gaza. The one-state solution would mean the end of the Zionist enterprise, because Israel can rule such an entity, in which there would soon be more Arabs than Jews, only by apartheid or ethnic cleansing. It would also mean the end of Palestinian nationalism, because the Israelis will crush the Palestinians rather than be evicted. That is the outcome we are heading toward, though, unless the only reality principle left, the United States of America, really intervenes — with its influence, its wisdom and, if necessary, its troops.