This year's Reith lecturer is British military historian and journalist John Keegan

In his second lecture, recorded at the Royal Military Academy Sandhurst, John Keegan looks at the origins of warfare, when combat first became purposeful, and examines whether evidence of violence and the need for war is embedded in human nature, or if it is only present in the external factors which act upon human nature. He argues that the evolution of conflict is inextricably linked to the evolution of social groupings.