The 2009 TIME 100

Somaly Mam and Cambodia's Khmer Rouge regime were born around the same time — when the U.S. began secretly carpet bombing her country. The bombed villages became fertile ground for the Khmer Rouge's growth and Pol Pot's revolution.

By the time Mam was 5, the Khmer Rouge controlled Cambodia and had proceeded to kill 1.5 million people as Pol Pot implemented his radical form of communism. Torture, executions and forced labor were widespread. Families fled for safety, and massive internal displacement decimated Cambodian society in the years that followed.

Against this backdrop, 12-year-old Mam was sold into sexual slavery by a man who posed as her grandfather. She eventually ended up in a Phnom Penh brothel, beginning a decade of horrific rape and torture. She describes this period of her life simply: "I was dead. I had no affection for anyone."

Terror is the weapon of choice for those who hold women in sexual bondage. They depend on their victims' being frozen with fear. Traffickers hope that with enough pain and degradation, women will simply accept their fate as inescapable.

But Mam was able to escape. With the help of an aid worker from France, she fled Cambodia in 1993.

The fact that she escaped makes her unique, but what makes her truly extraordinary is that she went back. While, understandably, most people would spend the rest of their lives quietly recovering from their wounds, Mam decided to confront the system that continues to victimize Cambodian girls.

In 1996, Mam created a nonprofit organization called AFESIP (Agir pour les Femmes en Situation Précaire, or Acting for Women in Distressing Circumstances) that works with local law enforcement to raid brothels and reintegrate the trafficked women into society. It is estimated that between 1.2 million and 2 million people are currently being held as sex slaves around the world. Mam, now 38 or 39 (she does not know her birthday), has established a model for addressing this issue and has already helped more than 4,000 women escape the brothels.

She has paid a terrible personal price for doing so, enduring death threats and assaults. In an effort to deter her work, brothel owners even kidnapped, drugged and raped Mam's then 14-year-old daughter in 2006.

Most people would have walked away. Mam continues to fight back so that others can be spared the pain she once suffered.

Jolie, an Oscar-winning actress, is a goodwill ambassador for the U.N. High Commission for Refugees and co-chair of the Jolie-Pitt Foundation