The rock hit Nili Philipp on the side of her helmet as she biked last year along the main road in this Jerusalem suburb. A few years earlier, the spitting had begun, as Philipp jogged on a road bordering an ultra-Orthodox neighborhood. Men called her names: Shikseh, the derogatory term for a Gentile woman. Prutzah, whore.

But Philipp’s story is not one of conflict between the defiantly secular Israeli majority and an increasingly assertive ultra-Orthodox minority. She is an observant, modern Orthodox Jew, dressed, on the day we speak, as she is for her runs — a kerchief covering her red hair, a skirt that falls modestly below the knee. It speaks volumes about intolerance among the ultra-Orthodox that Philipp has become enraged, even radicalized, by the behavior of her neighbors.

“Whenever people tell me, respect their society — their society doesn’t respect me,” Philipp says, voice quivering as she describes a recent incident in which a woman with an infant was pelted with stones while shopping here. “We all see ourselves as vulnerable, and we’re all scared.” The latest skirmish involves signs instructing women here to stay off certain sidewalks so as not to brush up against men.

In a chilling parallel to the escalating fundamentalist tendencies within Islam, the ultra-Orthodox, or Haredim, have adopted a version of Judaism that requires strict separation between men and women. The more they fear assimilation, the more extreme their practices have become. And, as their numbers mount, they have stepped up demands that society accommodate their religious needs.

On a day-to-day basis, the ultra-Orthodox, insular and detached, make little difference to the average Israeli. You can order a decidedly unkosher grilled calamari in Eilat or go clubbing in Tel Aviv even after Sabbath begins on Friday night.

Few secular Israelis experience the de facto segregated public buses that run through Haredi neighborhoods in Jerusalem; men sit in the front, women in the back, despite court-ordered signs advising passengers that they can sit where they choose. When I rode the No. 56 from Ramat Shlomo to Mea Shearim with representatives from the New Israel Fund and the Israel Religious Action Center, no one said a word when I sat up front — even if ultra-Orthodox men chose to stand rather than occupy vacant seats nearby.

Instances of intimidation such as Philipp experienced are more episodic than constant, more localized than countrywide. When they hit the news, as with the spitting and yelling at Philipp’s daughter and other young girls heading to their religious school in Beit Shemesh last year, there tends to be public outcry and, at least briefly, official intervention.

One difficult set of questions in a country where religion and government are officially entangled is how much the state should accommodate the religious needs of the ultra-Orthodox — for example, the ultra-Orthodox public radio station that bleeps out the voices of female members of the national legislature, the Knesset, lest men suffer from “impure” thoughts on hearing women’s voices, or public health clinics with separate days for men and women. If higher education is key to integrating the ultra-Orthodox, should the state fund scholarships for gender-segregated classes?

Even more troubling are the mounting instances in which the ultra-Orthodox have insisted that their religious needs take precedence — for instance, demanding separate seating at public ceremonies or even, as happened last year, barring a female pediatrics professor from going on stage to accept an award from the ultra-Orthodox health minister.

With the country now debating how to integrate the ultra-Orthodox into the armed forces — the long-standing draft exemption has been declared unconstitutional — questions of gender equity will become even more pointed: Will conscription of the ultra-Orthodox come at the expense of women’s rights in an egalitarian military? Will ultra-Orthodox men take orders from women?

These clashes between the legitimate rights of a religious minority and the essential freedoms of the majority threaten to become ever more intense as the ultra-Orthodox population multiplies and its political clout grows. The ultra-Orthodox now constitute about 10 percent of Israel’s population, but the Central Bureau of Statistics estimates that the Haredi share of the population will reach 30 percent within 50 years.

“I moved to Israel and the rock that was thrown at me wasn’t from an Arab, which I was prepared for,” said Dov Lipman, a Beit Shemesh community activist who came here from Silver Spring, Md. “It was thrown by another Jew, which I wasn’t prepared for.”

No one should have to be.