"I've got a near-torn Achilles," Henry Kissinger said outside the door of his apartment building. "Like Kobe Bryant," said Samantha Power, the United States ambassador to the United Nations, as she helped him into the van. "Who?" he asked as he settled into the seat for the ride to Yankee Stadium.

This past weekend, Ambassador Samantha Power gave her first speech as U.S. Ambassador to the United Nations to more than 1,500 young activists at Invisible Children's Fourth Estate Leadership Summit in Los Angeles.

I was a 20-year-old smart ass when I first picked up Samantha Power’s book, A Problem From Hell, in the fall of 2004. My international politics professor had assigned her thick chapter on Rwanda, so on the night before class, still smarting from a botched date in Philadelphia and hurtling toward Swarthmore College in a rickety SEPTA train, I opened to page 329. There I read about the inept American response to the massacre of 800,000 human beings in 100 days in 1994. And just like that, Samantha Power’s words changed my mind, and my life.