NICHOLAS D. KRISTOF: The Good Daughter, in a Brothel

BATTAMBANG, Cambodia

One of the oldest social dichotomies is the one dividing good girls from bad, the madonna from the whore. But in poor countries where sex trafficking and globalization have fostered new forms of slavery, it is the saintly ones — those who risk leaving their villages to help their families — who often end up as whores.

Yan Kosal is a 26-year-old woman here in northwestern Cambodia who was devoted to her aging parents and desperately concerned with providing for them. Her mother is blind, her father is frail, and they depend on her — the only surviving child — for food.

Kosal earned only $30 a month as a peddler, barely enough to scrape by. So when a woman acquaintance told her that she could earn $90 a month selling snacks in Thailand, Kosal leapt at the opportunity.

“I thought I should do this to feed my parents,” Kosal said, particularly because her acquaintance offered to escort her to Bangkok. Kosal borrowed $15 to pay her travel expenses, and they set out in September. But once they were in Thailand, where Kosal couldn’t speak the language, the trafficker sold her to a brothel.

“First, I cried,” Kosal said. But the brothel manager beat Kosal until she capitulated. “If the men wanted to go to the room,” Kosal said numbly, “the girl had to go.” The women were paid nothing, except for tips — but the sad ones who wept and were uncooperative didn’t get tips.

It’s difficult to gauge how common such forced prostitution is. But it appears that in much of Asia, the entry into prostitution is overwhelmingly unwilling (and in any case, the girls are typically too young to give consent). Then, once they have been stigmatized and have lost hope of returning to their families and villages — and in some cases become addicted to drugs — they often accept their lot and continue without coercion.

As for Kosal, she did manage to escape. Last month she and another young woman fled their brothel in the middle of the night and set off to walk back to Cambodia.

Kosal had begun suffering from abdominal pains while at the brothel, and by the time she returned to Cambodia she was severely ill. Kosal was too mortified to tell me the ailment, but her cousin said that it was a gynecological problem arising from sexual abuse.

With Kosal hovering near death, an aunt mortgaged her house for $250 to pay for medical treatment. That bought medicine that has kept her alive so far, but doctors advised that she needed surgery — which she can’t afford. The aunt, Khlat Dam, says: “There just isn’t any more money to pay for an operation.”

To Americans the phrase “21st-century slavery” may sound like hyperbole — but talk to women or girls who were imprisoned in modern brothels, and you realize that the main difference between them and 19th-century slaves is that the modern ones are dead of AIDS by their 20s.

This modern slavery thrives partly because it is ignored. But where there is an outcry and diplomatic pressure, they do make a difference.

On my first visit to Cambodia, brothels openly sold 11-year-old girls. Then, because of pressure from the State Department, Cambodia began prosecuting certain pimps (like those who do not pay enough in bribes to the police). So many brothels have calculated that they are safer peddling quasi-voluntary 16-year-olds than imprisoning 13-year-olds.

Yet stories of slavery like Kosal’s are still wrenchingly common, and corrupt officials protect many traffickers. On this visit, I stayed two nights at a guest house whose ground floor was a brothel with girls who were obviously under age. The guest house is owned by a senior police official, who evidently has decided not to arrest himself.

A century and a half ago, the British determined that slavery was an intolerable evil and used their navy to confront the trans-Atlantic slave trade. Several groups are pushing for a new abolitionist movement today (I’ve posted links, and suggestions for helping Kosal, at nytimes.com/ontheground). Now President Bush needs to make abolition of 21st-century slavery an American priority.

If he needs inspiration, he can look to Kosal. This is a courageous young woman whose only goal was to help her family members. Instead, she has bankrupted them and endangered her life — and risked her parents’ future. This failure gnaws at her: “It may be my time to go now,” she said sadly, “and I’m the only one left to support my parents.”