In the cramped neighborhoods of Jerusalem, a battle is being waged that officials fear may someday alter dramatically the character of the city that is holy to three of the world's great religions.
It is a battle between the expanding ultraorthodox Jewish community and Jews who live in any neighborhood into which the ultraorthodox decide to move.
And it is a fight the ultraorthodox appear to be winning.
In recent years, entire neighborhoods that once were home to a cross section of Jewish society have been transformed into communities where only the ultraorthodox live. (The ultraorthodox also are referred to as Haredim or Hasidim. Hasidic men are distinguished by their long beards and sidelocks and by the black clothes and hats they wear.)
The Jerusalem Hasidim once lived almost exclusively in Mea Shearim, one of the oldest neighborhoods built outside the Old City walls.
But as the Hasidic community has grown, its members have overflowed into other neighborhoods.
The result is that the less observant or secular Jews are abandoning the city for the suburbs or for Tel Aviv.
City officials and other concerned observers said the fight between Israel's extremely orthodox Jewish community and Jews who are less religiously observant is one of the most serious conflicts in a society already badly splintered along political, ethnic, and cultural lines.
''It is very dangerous to the culture of Jerusalem. Jerusalem is a center of all the world. It is the heart of the Jewish people all around the world, not just the Haredim,'' said Rafi Davara, a spokesman for the Jerusalem municipality. ''It is unfair to the Jewish people and to other people to let the Haredim take over.''
Mr. Davara said that the Hasidic community in Jerusalem is growing at a faster pace than other communities. The city estimates that 600 new ultraorthodox couples each year look for housing in Jerusalem. Of Jerusalem's 430,000 people, 70 percent are Jewish. Of the Jews, it is estimated that 18 percent are Hasidic, and 12 percent are ultraorthodox, but not Hasidic, Davara said.
A combination of factors has intensified the conflict in recent years between the Hasidim and other Jews.
First is the sheer growth in the ultraorthodox community, both in natural increase and in the number of ultraorthodox immigrating to Israel. Such immigrants tend to gravitate to Jerusalem, where many of the most important Hasidic rabbis and schools are.
Second is the political climate that has existed under the Likud government for the past seven years. Under the Likud, the ultraorthodox enjoyed increased funding and enhanced political power. More money and more prestige have made the ultraorthodox more aggressive.
When the ultraorthodox control a neighborhood, they demand that its streets be closed to traffic during the Jewish Sabbath - sundown Friday to sundown Saturday. They also demand that those who live in the neighborhood dress modestly and refrain from playing radios or watching television during the Sabbath.
''In recent years, there seems to have been a breaking of this delicate balance that exists. The ultraorthodox are driving all sorts of people out of the city,'' said Barry Chazan, a professor of religion at Hebrew University.
''It is not just a small group of (ultraorthodox) kids throwing stones. It is an organized, systemized plan to conquer neighborhoods,'' Professor Chazan said.
For Shoshona Levy, that systemized plan became a very real struggle for her and her family two years ago on a Friday night.
Ms. Levy, not her real name, was at home with her four children in the Mekor Baruch neighborhood. Her husband was at work, she said.
''We heard someone start yelling outside in the street, 'Sabbath! Sabbath!' '' Levy recalled. ''My daughter ran to the door to see what was happening. She was wearing a short nightgown. There was a religious man standing outside and when he saw her he screamed, 'Zona!' ''
The word means prostitute in Hebrew. The Hasid had hurled the epithet at Levy's teen-age daughter because she was dressed immodestly by the standards of ultraorthodoxy. Ultraorthodox women usually wear long-sleeved dresses that come well below the knee.
A neighbor who heard the exchange rushed to defend the honor of Levy's daughter.
''But a whole group of the religious came out, and they hit him (the neighbor) and broke his nose,'' Levy said.
Levy, an immigrant from Morocco who considers herself to be religious, has lived in Mekor Baruch 17 years. Although many of her friends have left, she said , she will stay.
''I have my house, I will stay. But it is a very big problem. When we lived in Morocco, we lived with the Arabs and there was no problem. Here, we have problems with our own people. They do not respect us.''
There have been other incidents, according to Mekor Baruch residents and city officials. When the ultraorthodox families began moving into the neighborhood a few years ago, they would offer to buy homes (usually at a higher-than-market rate), and if refused, would sometimes resort to threats.
A group of secular Jews living in the neighborhood attempted to form an opposition group to the influx of the religious. The municipality attempted to mediate by opening a community center that tried to attract members from each group. But the ultraorthodox refused to come to the community center. It closed, and the opposition group disbanded.
''Mekor Baruch is lost,'' Davara conceded.
''It's really a war going on,'' said Jeff Halper, an anthropology professor at Hebrew University. Professor Halper recently participated in a lawsuit filed by another Jerusalem neighborhood against an ultraorthodox group that wanted to open a yeshiva (a seminary for training orthodox rabbis) in Nahalat, a predominantly Yeminite community.
Residents of the neighborhood, including Halper, who has lived there 13 years , sought and received a court injunction against the yeshiva on the grounds that it would alter the neighborhood's character. The yeshiva's founders have since said they will locate in another neighborhood.
''We're not opposed to ultraorthodox people living in the neighborhood,'' Halper said. ''You have all different kinds of people living here, religious and secular, new and old. Everybody lives together. There's a tolerance. We are opposed to an ultraorthodox institution in the area.''
Critics of the secular Jews who have opposed the ultraorthodox have said that the Nahalat incident was blown out of proportion, that the yeshiva would not have disrupted the neighborhood because it was a yeshiva of ultraorthodox from the United States, who are usually more tolerant.
''The nonreligious people in Israel have a certain kind of animosity and hatred of the ultraorthodox,'' said Shaul Magid, an orthodox rabbinical student who lives in Mekor Baruch.
Mr. Magid, an immigrant from New York, was himself ultraorthodox for a time and wore the traditional black coat and black hat of the Hasidim. Today, he said , he is still strictly observant religiously, but has left the Hasidic community , which he found to be too insular.
''I think I have somewhat of an understanding of both sides,'' Magid said. ''The tension between the religious and the non-religious in Israel is very, very powerful. Any Jew who comes to live in Israel, has to confront the religion in himself.''
Secular Jews often resent the Hasidim because they are anti-Zionist. Many Hasidim do not participate in the politics of the state of Israel, because they believe that a Jewish state can only be established when the Messiah comes. Even the Hasidic religious party, Agudat Yisrael, will participate in governments but will not hold Cabinet portfolios.
''We hate them (the Hasidim) because we look at them and see what we used to be,'' said one secular Israeli.
Magid and others explained that the intolerance the Hasidim feel for other Jews stems from the fact that most came - or are the children of those who came - from Eastern Europe. Eastern European society before World War II dictated that Jews lived in isolated communities, or shtetls, and were kept separate from the gentile society. The ultraorthodox today perpetuate that isolation in Israel.
''The Hasidim, they always go in groups,'' Magid said. ''When they make a decision to extend a neighborhood, they do it like a force. They're always looking for a shtetl and any place they move, they are going to try to create that.''
Davara, the spokesman for the Jerusalem municipality, said the city recognizes that need and has tried to accommodate it.
''We have built new, modern neighborhoods just for the Haredim,'' Davara said. ''We want to build more Haredim neighborhoods.''
But Davara said that despite the fact that the homes are modern and less expensive in the suburbs planned especially for the ultraorthodox, many still seem to prefer inner-city housing.
''They hope that Jerusalem will be religious,'' Davara said.
''I respect how they keep the Jewish religion, but I don't want to live like the Jews lived 2,000 years ago.''