ast Wednesday was a day of celebration for many in Gaza City. They handed out sweets and thousands danced in the streets. The cause: seven Jews, five of them American, had been massacred by a remote-control bomb at Jerusalem's Hebrew University. Soon, Israeli armored vehicles were tearing through the West Bank city of Nablus and Israeli troops were blowing up homes of refugee relatives of suicide bombers.

Nearly two years of this cycle — accelerating Palestinian terror and Israeli military reprisal and occupation — have numbed us to the horror. The killing goes on over there, life goes on over here. The murder of five Americans brings it home.

Marla Bennett, a 24-year-old from San Diego who was among those killed, liked to write about life in Jerusalem. Last May Ms. Bennett wrote that each decision — whether to turn right or left — could be life threatening. But, "if I am here I can take an active role in attempting to put back together all that has been broken. I can volunteer in the homes of Israelis affected by terrorism, I can put food in collection baskets for Palestinian families."

Anyone who has spent time in Jerusalem knows young Americans like Ms. Bennett — idealistic searchers for whom the study of ancient Jewish texts is brought to life by the pleasure of wandering the city's stony back streets. No matter how frightening it had become, Ms. Bennett said she was alive in Jerusalem in ways she had never known before.

There will doubtless be fewer idealists willing to study in Jerusalem just now. This is a shame because their spirit and openness are in increasingly short supply there. Public sentiment on both sides has hardened into a kind of tribal rage that sees only its own pain. When on July 23 the Israeli military decided to kill Salah Shehada, a top Hamas terrorist, it dropped a one-ton bomb on his apartment in an area as densely populated as Manhattan's Upper West Side. Fourteen others, including nine children, were killed with him.

The point here is not that the deaths of innocents caused by Israel's attack and Hamas's blatant act of terror are morally equivalent. The point is that they are both terribly wrong. Yitzhak Frankenthal, who lost his son to Hamas terrorists in 1994, leads a group of Israelis and Palestinians who have lost children to political violence. He said that if Israeli soldiers had his son's killers in their sights but knew that innocent Palestinians would die as well, he would demand they hold their fire.

"It is unethical to kill innocent Israeli or Palestinian women or children," he said. "It is also unethical to control another nation and to lead it to lose its humaneness."

Israel cannot take the blame for causing the Palestinians "to lose their humaneness." Palestinians must search their own consciences for the depravity of dancing in the streets in celebration of death. But there is plenty of searching for Israel as well. Blowing up homes of terrorists' relatives will not end the terror. Nor will it help create the conditions that will bring more young Americans like Marla Bennett to Jerusalem.