JERUSALEM -- If they hadn't been stirred already by the female soldier who was called a "slut" on a public bus, or the 8-year-old girl spit on by neighbors on the way to school, the sight of Jewish protesters dressed up in concentration-camp garb seems to have pushed much of Israeli secular society over the edge.

It happened last weekend, during a demonstration against what protesters perceived to be an unholy government incursion into their way of life: several hundred ultra-Orthodox Jews staged a rally in Jerusalem, dressed as concentration camp victims.

The protesters, part of an ultra-religious group known as Haredim, were dismayed that the government had taken down signs in their communities demanding that women walk on the opposite side of the street.

Later, two ultra-Orthodox men were arrested for releasing fliers comparing the government's treatment of Haredim to the treatment of Jews in Nazi Germany.

"We made it through Hitler, and we will make it through his successor," one of the fliers read.

Israel's top politicians expressed dismay. Elie Wiesel, the Israeli Nobel Prize winner and Holocaust survivor, called the whole thing a "vile sight."

The protests were just the latest in a string of provocative incidents involving the Haredim, which have rattled Israel's secular mainstream.

Shortly before Christmas, Israel's top news channel aired a documentary about the eight-year-old, Naama Margolese, which described her terror at being cursed and spit on during her walk to school. The incident -- which supposedly occurred because Margolese was dressed too immodestly -- occurred in the ultra-Orthodox town of Beit Shemesh.

A few days later, a female soldier -- who some have labelled the "Israeli Rosa Parks" -- tangled with a Haredi who insisted that she move to the back of the bus so that men wouldn't have to sit next to women; he ended up calling her a "slut."

The rise of ultra-Orthodox aggression is not new; Jerusalemites have long known not to walk through certain religious neighborhoods, like Meah Shearim, without being properly dressed, or while talking on the phone during the Sabbath, for fear of being spit on or having a dirty diaper land on their head.

But the rash of incidents in the past few months, and the expansion of the confrontations outside of the Haredim's isolated communities, has forced Israeli society to confront a growing challenge -- and a demographic reality.

As it is, the Haredim compose only a small fraction of the national population -- around 10 percent, experts say. But their birthrates are much higher than the general population, and by mid-century, according to some estimates, Haredim could make up between a quarter and 40 percent of Israeli society.

Meanwhile, Haredim members of the Knesset, Israel's parliament, have also long-held important roles in governing coalitions, and have lately begun aggressively pushing legislation that would codify some religious rules.

"The Haredim love to say that they're a minority," said Shahar Ilan, a former religion correspondent for the Israeli daily Haaretz. "But they have been part of our political majority for 35 years -- and a brutal part. This is how they have to be understood."

Ilan is now the vice president of research at an organization called Hiddush, where he works to promote religious tolerance, as well as an awareness of the ways in which extreme forms of religion have imposed themselves on everyday Israeli society.

"Have you noticed that there are no pictures of women in Jerusalem at all?" Ilan said recently, at a cafe in the liberal, upscale German Colony neighborhood.

When Israel's national organ-donation group ran a major publicity campaign in Jerusalem recently, Ilan noted, they agreed to include no images of women in their billboards, out of respect for the sensibilities of the ultra-Orthodox.

"And yet, the Haredim will take our organs but they refuse to donate theirs," Ilan said. "They see it as a violation of Jewish law -- the killing of a still partially-living thing. But we still accommodate them in the advertising?"

The Haredim do not work, and they refuse to serve in the Army -- indeed, the most extreme of them reject the legitimacy of the state of Israel itself.

At the same time, they are largely dependent on nationally-provided welfare to feed and clothe their families; their education system, which does not include most of the core Israeli curriculum of math and sciences, is also funded by the state.

"The Haredim are guilty of three violations," Yossi Klein Halevi, a prominent Israeli essayist and fellow at the Shalom Hartman Institute in Jerusalem, said. "First, they are separate from us, and they don't share in the burden of defense or taxes. Second, they demand that we subsidize them. Third, they propose to force their religious beliefs on us. It's a level of chutzpah that I don't think any minority in the world would allow for itself."

Shalom Lerner, the Orthodox former mayor of Beit Shemesh who has emerged as a critic of the radical elements of his community, says part of the problem of the Haredim is that they are not well understood -- and do little to help bridge that divide.

"They try to hide the problem and they are very defensive, you tell them you have a problem they'll say no, you have a bigger problem," Lerner said.

When an Israeli newspaper interviewed the Haredi who had insulted a woman on the bus, the man, Shlomo Fuchs, said he would not forgive the female soldier for having robbed him of valuable religious study time.

"She protects me?" Fuchs said, indignant at the thought he should lend special consideration to a soldier. "I sit at shul from eight in the morning till midnight and study, and she's protecting me? I protect her."

Fuchs also claimed that he didn't even really know what the word "slut" meant.

"I am completely detached from the (secular world)," he said. "I don’t own a television set and I never have newspapers in the house."

Lerner said, "I think sometimes they're not sensitive to the impact of what they're saying because to them, the fact that a woman and a man should not sit together on the bus, it's so obvious."

"They really don't know," he continued. "They don't interact with our culture until it's become confrontational."

Lately, a confrontational attitude -- even veering toward outright anger -- dominates the mainstream secular Israeli's take on the Haredim.

"Ultra-Orthodox extremism has darkened our lives," Efraim Halevy, the former head of Israel's spy agency, Mossad, recently said. In the same remarks, he also described the Haredim as a greater threat to the nation than Iran.

"I would use a different word," said Gideon Levy, a popular liberal columnist at Haaretz, when asked about the apparent anger toward the Haredim. "It's hatred."

Levy sees the popular uproar as little more than an easy distraction from the real problems that plague Israeli society, particularly the Palestinian issue.

"The emotion is really out of proportion, while neglecting so many other things," Levy said. "It's an outlet to make people who feel that they're not really doing enough to strengthen our democracy and the Israeli liberal spirit -- so why not do it in the easy way, which is to fight Haredim."

Even centrist ultra-Orthodox Jews have joined in the criticism, in part worried that the entire community would become tainted by the actions of the extremists. But for those who see the Haredim's incursions as a threat to the Israeli national experiment, the danger feels very real.

"Israelis want to make some semblance of a common space for all of our tribes," Yossi Klein Halevi said. "Here we have all of these disparate groups forced together in a pressure cooker. The question is, 'Is the pressure cooker working to bring all Israelis close together, or is it driving us insane?' Right now it seems to be working as a centrifugal force."