The seventh- and eighth-grade students in Nancy Mazgajewski's humanities class studied the killings in Sudan's Darfur region for weeks.
They gave presentations to fellow students at Orchard Valley Middle School and wrote letters to such officials as Kofi Annan, the United Nations secretary-general, and Condoleezza Rice, U.S. secretary of state.
So, on Thursday, the students were ready with tough questions for a one-hour videoconference with a U.N. representative.
Gina Parker, 13, wanted to know why the U.N. calls the killings "war crimes" and "crimes against humanity" but not genocide.
The designation is important because it determines how criminals are charged and the punishment they face.
Human rights groups and the United States say genocide is taking place as pro-government Arab militias kill black Africans, who are predominantly Muslim, and destroy their villages, livestock and crops.
An estimated 70,000 people have died and 2 million have left their homes.
"Genocide means there's an intentional, deliberate act to uproot and eliminate a whole group of people," said Hamid Abdeljaber, with the U.N. Department of Public Information.
Speaking from New York City, Abdeljaber described genocide as the "most flagrant case" of a group crime and said a U.N. team sent to Darfur determined the offenses didn't rise to such a level.
Student Erin Dunphy inquired about Sudan's south where a civil war raged for 25 years between Muslims in the north and Christians and animists. A peace agreement was signed in January.
A U.N. peacekeeping force is now arriving in the south, and Dunphy, 13, wanted to know why the mission wasn't started sooner.
The U.N. has many missions, Abdeljaber responded, noting resources are stretched thin because of involvement in places like Bosnia, Haiti and Cambodia.
After the discussion with Abdeljaber, some students said they thought it was interesting how the U.S. and the U.N. disagree on terms, though they are on the same side of the issue.
"I think it's kind of disgusting and horrible how they are killing people" and leaving the survivors with nothing to return to, said David Samsel, 14.
The students, part of the school's gifted and talented program, began investigating the Darfur crisis after learning about the Holocaust, Mazgajewski said.
Last week, they organized a Sudan Awareness Week and visited all of Orchard Valley's social studies classes - about 30 - to address the topic.
The students have sold 200 green "Save Darfur" bracelets and ordered 400 more to raise money for the Sudan relief effort.
On Monday, several students will participate in a Junior Model United Nations event at La Salle University in Philadelphia and present their report on Darfur to about 275 students.
They plan on continuing to write letters to the Sudanese embassy and elected officials, including President Bush.
Mazgajewski said she is trying to teach her students that "they are not just United States citizens but are citizens of a global community."
It was a message Abdeljaber reinforced throughout his discussion with the students, saying no country is an island unto itself and that everyone must help ease turmoil.
"We are like passengers on the same ship," he said. "If one part of the ship is wrecked, than we all are not safe."
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