In 2006, I was surprised to find myself sitting at a formal dinner in the middle of a 200-year-old debating society at Cambridge University in England. In a few minutes I, and five others were about to engage in a debate over the usefulness of the United Nations. But here, for a few minutes longer, at the long dinner table with the crisp, white tablecloth, I was sitting next to one of my fellow debaters, Salis Shetty, the head of the UN’s Millennium Project. I had ignored him through most of the dinner, but with just a few minutes left...