What is the United Nations for, what brought it about, and has it lived up to expectations? As a new Secretary-General takes over, Bridget Kendall and guests give all you need to know about the world’s most ambitious public body. Joining Bridget Kendall are Jussi M. Hanhimäki, professor of International History at the Graduate Institute of International and Development Studies in Geneva; Heidi Tworek, fellow at the Transatlantic Academy and assistant professor of International History at the University of British Columbia; Carolyn Medel-Anonuevo, head of the Education Unit at Unesco’s Southern Africa regional office in Zimbabwe; Lord Mark Malloch-Brown, who served as Deputy Secretary-General and Chief of Staff of the UN under Kofi Annan. Photo: The United Nations building in New York. (Getty Images)