Does power corrupt, or are corrupt people drawn to power? It’s a question that runs through the heart of the work of Brian Klaas, professor of global politics at University College London and Washington Post columnist. His latest book is 'Corruptible: Who Gets Power and How It Changes Us', which looks at the psychology behind those who seek power. Pulitzer-prize winning historian and journalist Anne Applebaum speaks with Brian about what the book reveals.