Nobel Peace Prize winner Leymah Gbowee drew cheers at the Women in the World summit Friday morning, telling the crowd, “It’s time for women to stop being politely angry.” She was referring to the recent political firestorm in America over contraception and abortion. “Why are these women not angry and beating men left and right?” she asked, adding that men aren’t qualified to dictate women’s reproductive rights, since they’ve never given birth. “You only qualify if you’ve gone through the process—you understand what the process is.”

Gbowee knows something about telling off men. She won the Nobel prize this past fall for rallying women in her native Liberia to vanquish a dictator and demand peace in the war-torn country. In a frank and colorful talk with Tina Brown, Gbowee, now 40 years old, described how she was 17 when war broke out in her country. At the time, she said, she did a “total flip,” transforming from a dependent teenager with dreams of medical school to an immediate adult, responsible for finding food for 20 extended family members.

When Brown asked how she adjusted to her new reality, Gbowee said, “You never really adjust. You’re just existing. You’re alive. There’s nothing to look forward to. Every day, I went out to look for food. I saw bodies, people being shot. My mother had sunk into a state of total traumatization.” She added that she was so focused on her daily mission to feed the family that she didn’t notice one day when armed men were shouting at her to stop at a checkpoint, pointing their guns straight at her. “People were screaming at me,” she said, laughing.

Gbowee said she spent more than a decade simply trying to survive and “waiting for a white knight.” Finally, she said, when she was 31, “I realized, no one will come.” That’s when she started mobilizing women to demand peace. “We have to be our own Gandhis, our own kings, our own Mandelas,” she said. Gbowee began organizing sit-ins and demonstrations—and even a “sex strike” in which women withheld sex from the men in their lives. She convinced women to dress in white day after day and join the peaceful protest, starting with five women, she said, and eventually growing to thousands across 20 cities.

Men were “shocked at the tenacity of the women,” she said, noting that these were women who had been raped and victimized, and were now standing up to—and talking down to—men. “The men were looking at us and saying, ‘Is this for real?’” she said. “They couldn’t believe it.” She added, “This is a lesson for any women looking for something from men. As long as we continue in a position of weakness, they will never respect us.”

In a particularly rousing moment from the talk, she described how she once rallied a group of women to lock arms and sit outside a conference hall full of male leaders in Monrovia, telling the men they could not exit until progress toward peace was made. “Security came and said they would arrest me because I was obstructing justice,” she said. “This made me angry.” She threatened to strip naked right there, and the guards backed off.

She is credited, along with fellow Nobel Prize winner Ellen Johnson Sirleaf, the president of Liberia, with ending the country’s 14-year civil war.

Read more about Gbowee, a Daily Beast contributor, in her Beast Book Mighty Be Our Powers.