Actress and humanitarian activist Mia Farrow told students on Wednesday about her own experiences working with refugees of genocide in the Sudan, Chad and throughout Africa, and urged community members and students to speak out against injustices occurring in many parts of Africa.

Farrow, who serves as a UNICEF goodwill ambassador, began her Assembly Series presentation with a tribute slideshow set to John Lennon’s “Imagine.” The slide show featured photographs she has taken on her 13 trips to Africa depicting children affected by the violence.

She proceeded to list the various genocides of the past century, claiming that, with death totals amounting to more than 100 million people, these mass-atrocity crimes pose a greater threat to humanity than war.

“Genocide and mass atrocities are not inevitable,” Farrow said, “It begins with a choice.”

Turning a blind eye to these atrocities, she argued, also constitutes a choice, a shameful one.

“Those with the power to halt the killing choose to do nothing,” Farrow said. “So we all have a role here. In the international community, we have played our role as bystanders over and over again.”

In a question and answer session after her talk, Farrow expressed her disappointment and disgust with the lack of action from the United Nations, saying the body has fallen far short of its original intentions, and she called for stronger leadership.

“We’ve never made good on our responsibility to protect. ‘Unacceptable’ means nothing,” she said. “They [the U.N.] need to go spine shopping.”

Farrow also said that she regretted her lack of involvement in combating, or even knowledge of, the 1994 genocide in Rwanda. She called the genocide in Darfur “Rwanda in slow motion” and spoke of her conviction to do something about it this time, vehemently urging the audience to acknowledge the importance of this attitude.

Farrow presented another slideshow to provide the background and context of the Darfur genocide, which began in February 2003 and has claimed the lives of 400,000 people and displaced more than 250,000. She showed photographs of crowded refugee camps, which she said are subject to frequent attacks of killing, rape and torture by the Arab Janjaweed, a militia whose name translates to “devils on horseback.”

“Water, food: insufficient,” she said of the dire situation in rapid fire. “Medical care, education: insufficient to nonexistent. Hope: insufficient to nonexistent.”

During her visits to Africa, Farrow said that one of the most heartbreaking parts of the experience each time was the constant stream of pleas for protection.

“I don’t think there can be a more visceral plea from the human heart: ‘Protect us. Save us,’” she said. “After seven years, what message have we sent to these children? Only that they are completely dispensable.”

The activist spoke of the pain that she feels at leaving the horrific suffering of the people in Darfur behind and returning to a largely indifferent world after each visit to Africa.

In response to a student who asked Farrow for advice about how best to get involved, she said, “Be outraged. Be unreasonable. It’s the holler-and-screamers that get things done,” Farrow said.

Farrow said that in the United States, average citizens with freedom have a responsibility to uphold, to use their power and their voices in a democracy to help others.

“We have to do our utmost,” Farrow said.