John Ryle is co-founder and former Executive Director of the Rift Valley Institute and Legrand Ramsey Professor of Anthropology at Bard College, NY. He has worked as a long-term social researcher in Sudan and in Brazil, as a regional analyst for aid and human rights organizations in Africa and the Middle East, and as a writer, editor and broadcaster worldwide. He is author of Warriors of the White Nile (1984), an account of the Dinka of Southern Sudan, coeditor of The Sudan Handbook (2011) and a contributor to publications including the New York Review of Books and The Guardian, where he was a weekly columnist from 1995 to 1999. He is a Research Associate of the School of Oriental and African Studies, London, and a board member of the Media Development Investment Fund and the Human Rights Watch Africa Division.