"If someone is very far from Islam and doesn't consider religion, sometimes force is needed," she said softly. "If it's a little problem -- a little hair showing -- we can solve that by talking. But if it's many times that we've had to say to someone 'This way is wrong,' then it's time to use force." The official punishment is the lash, the number of strokes determined by the severity of the infringement. Usually, she said, the hard cases are the wealthy girls. "Most rich people are careless. The rich are proud -- they can't understand Islam or the revolution and its importance to us."

As I talked to Shahbonu, I could sense the growing tension of the translator sitting beside me. There had been a misunderstanding, earlier that day, about precisely what I had employed her to do. I had hired her through friends in Amol, and she had somehow gotten the impression she'd been hired to translate at a wedding party for Westerners. When I picked her up, she was wearing a miniskirt under her coat and a filmy scarf on her head. When she learned we were heading to the mosque, she ran inside in a near panic and changed into dowdy black trousers, tunic and maghnaeh.

Inside the mosque, surrounded by a crowd of women in chadors, I could tell she was nervous, even frightened, although everyone was treating us courteously. Later, she explained her fear. All her life, girls like Shahbonu had stood between her and almost anything she wanted to do, from walking with friends in the local park to securing the right to study. Despite her loathing for these women, she confided that she had, herself, worn a chador, "for the last two years of high school, so they would let me go to the university." It had astonished her that the huge mosque had been so crowded for the wedding ceremony. "Amol is a small town, and I've lived here all my life," she said. "But I didn't know anyone in there. I don't know anyone who has ever been in there. And I don't think I could find a relative or a friend who knows anyone who has ever been in there."

A FEW MONTHS AGO, A group of baseej recruiters came to Laila Sayed's school in north Teheran and invited her to join. Sitting with her brother Yousef on a sofa in her parents' sitting room, she tugs a Harley-Davidson baseball cap over freshly shampooed hair and giggles at the ridiculousness of the offer. "They said, 'We'll take you hiking in the mountains.' Great. But wearing a chador? No thanks." The chador -- a large black square of fabric draped over the head and held in place across the chin -- is now worn only by Iranian women who are very pious, very political or very poor. Laila doesn't want to be mistaken for any of these. Baseej membership's main asset is preferential university admission: about 30 percent of every class is reserved for war veterans, children of revolutionary "martyrs" or baseej whose grades otherwise wouldn't merit admission. Laila, an excellent math student, doesn't expect to need a quota to qualify.

Laila's high school is a sprawling building, still under construction in a desperate race with the demographic bulge. Of the 300 students in the two senior classes, only 4 or 5 wear chadors. The rest, like Laila, wear less severe maghnaehs and long tunics dressed up with athletic jackets or army-surplus coats.

She used to pray but says she gave it up a few months ago. "I got tired of the religion teacher's lies," she says. Her voice, unusually deep and husky for a 14-year-old, takes on a high, querulous pitch as she mimics the teacher: " 'Everything in the West is bad; everyone in America is going to hell when they die.' They know it's not true, so why do they say it?" Her brother Yousef says he has never prayed. While he has excellent grades in all other subjects, he is failing religion and Arabic, a subject he hates because it is associated with praying and reading the Koran.

Yousef's disaffection with religion is all the more striking because his father, to whom he is very close, is intensely devout and a strong supporter of the Islamic revolution. "The Koran says there is no compulsion in religion," Yousef's father says, explaining why he tolerates his children's behavior. "God willing, they will come to the right path in their own time. If I force them, I might drive them away from it."