An eerie silence descended last night and today over Israel, a country at war with itself on a troubled Yom Kippur.

In this, a holy city to three faiths, the traffic disappeared from the streets of Jewish West Jerusalem, stores closed, the state-run radio and television networks went off the air. Yom Kippur, the Day of Atonement, the most sacred day in the Jewish calendar, is a day for quiet reflection and prayer, for coming to terms with one's standing in the eyes of God.

This Yom Kippur, in homes and synagogues across the land, Israelis were also coming to terms with where their history had led them. How was it that this proud and persecuted people stood accused by many of complicity in a mass murder?

They had gone to war in June to free their northern communities from the terror of the Palestine Liberation Organization. Never again, they vowed, would the towns and villages of Galilee live with the constant fear of rockets indiscriminately raining down upon them from across the Lebanese border, or of the PLO raiding party bent on killing their people.

They did not know then that it would lead them to places called Shatila and Sabra, or that their television screens would show them the mangled bodies of Palestinian refugees, slaughtered by their Lebanese Christian allies under the glare of flares fired by the Israeli Army.

For some, the cause of their new moral dilemma was simple. It lay in the "evilness" of Menachem Begin, Ariel Sharon and their associates. "This crazy government must go," said a young man, one of the thousands who jammed a downtown square in Tel Aviv Saturday night to demand the government's resignation.

For others, the simple cause lay elsewhere. It was in the wanton terror of the PLO and the hypocrisy of the outside world that had stood by during the Nazi Holocaust, and now it was ready to condemn Israel for the acts of Christians while turning its eyes from the crimes that continue to be committed against Jews.

Yet as the dimensions of the massacre came into focus, most Israelis seemed unable to escape some sense of accountability. Sorting through his own complicated feelings, Moshe Zak, the editor of Maariv, a conservative newspaper that supports the government, wrote in an agonized personal column: "We have sinned, but we have not acted treacherously. We are ashamed and even abashed, but we have not murdered or covered up murder."

Once before, in 1973, there was a troubled Yom Kippur. On that day, an Israeli Air Force jet buzzed the holy city, one of several prearranged signals to tell the people to turn on their radios from which, unexpectedly, they heard a voice telling them that once again Israel was at war with the Arabs.

This time the war was within.

It is the question of Israel's accountability, and how to come to terms with it, that is most troubling. The massacre has happened; there is no way to bring the Palestinian refugees back to life. But Israel must go on living with the memory.

Nursing a beer the other day, one of Begin's strongest supporters said glumly, "We seem to have lost control of our moral barometer."

He was, like many Israelis, a disillusioned partisan, appalled by the carnage in Beirut, deeply worried about his country's future if it and its government did not face up to the responsibility that was theirs.

"To live out here in this part of the world you have to do some harsh things that do not fit our character," he said. "To be able to do it, we had to be absolutely sure of our rectitude, and we always were.

"What happened at Shatila and Sabra I still believe was no more than an enormous mistake. But the inability to see our moral responsibility, and to act on it, threatens that very feeling of moral certainty that has sustained us. If we don't blame ourselves, we subject ourselves to the moral criteria of others."

He is not alone in his search for the right measure of accountability and for the leadership to face up to it. At the huge antigovernment rally in Tel Aviv Saturday, a young woman of Canadian birth, a liberal activist, scanned the crowd for men wearing skullcaps, a sign that the orthodox religious community might be breaking with the government.

She saw very few. The religious community, like much of Israel, seemed stunned and confused in the aftermath of the massacre. The chief rabbis did not speak out until today, when one of them, Shlomo Goren, addressed a congregation that included the prime minister.

He called on Israel to stop its internal conflict. Israel, he said, should not be forced to repent for sins it did not commit.

Still, as the Begin government was dragged only grudgingly toward allowing an independent judicial board of inquiry to investigate the killings, some in the religious community were moved to do the unexpected. They took to the streets in protest.

On the eve of Yom Kippur, about 100 of them gathered across the street from Jerusalem's new Great Synagogue for the traditional afternoon prayers. They carried signs demanding that the commission be established. With their backs to the synagogue, they faced, as tradition dictated, to the east, peering toward the Old City and the Temple Mount beyond. Bowing, they chanted the ancient prayers, then listened to some of their leaders.

"We didn't pull the triggers, but in terms of repentance we are also responsible," one of them said.

"We have sinned, we have sinned with heavy hearts," intoned another.

"When we say these prayers," said a third, "we are saying that the guilt of our leaders is the same as our guilt. We are willing to accept responsibility because we are one nation."

Instances of cruelty and bloodshed are not new to the Jewish people. They are burned into their collective memory. They are burned as well into the left forearm of a short, squat man with thinning white hair and an ugly blue number from one of Nazi Germany's death camps.

Watching the demonstration, the man's face reddened with anger.

"Why did these people not demonstrate when the Arabs killed at Qiryat Shemona?" he said, referring to one of the northern Galilee towns where the PLO had struck murderously.

"My whole family was killed by the Nazis. No one demonstrated for them."

One of the religious protesters turned to him, asking, "Do you want to be like the PLO, like the Nazis? Do you want to be on their level?"

If Yom Kippur did not exist in Jewish tradition, Israel would have to invent it. For besides its principal religious purpose, it provides a respite from the march of events that press in on a small country in a dangerous part of the world.

In the spring there was the return of the Sinai to Egypt and the uprooting of the last holdout Jewish settlers at Yamit. Soon after, the West Bank exploded in rioting, reminding Israel that for all its vulnerability through history it is today an occupying power in the Middle East.

Then, with barely a pause, came Operation Peace for Galilee, the siege of Beirut and evacuation of the PLO, and finally Shatila and Sabra.

But on this day, when it is forbidden to drive and there is no news blaring over the airwaves, families strolled along normally busy streets, fathers pushing babies in their carriages. The Christian and Moslem sectors of the Old City were alive with people and merchants hawking their wares, but in the Jewish quarter it was quiet except for the chanting of the devout.

By late afternoon, the receding sun turned the sky above the hills to the west from blue to orange to purple, signaling the coming end of the holy day. Soon it was dark and the first sounds of traffic jarred the tranquility of the evening. Jerusalem began to stir back to life and to prepare to face another day.