Start the Week is at Hay Literary Festival this week discussing war and intelligence. Michael Hayden is a former Air Force four-star general who became director of the US National Security Agency and then the CIA. He talks to Tom Sutcliffe about the decisions made during America's war on terror: from rendition and interrogation to widespread surveillance. Harry Parker was in his twenties when he signed up to join the British Army - he uses the paraphernalia and weaponry of war to tell the story of conflict; while the journalist Janine di Giovanni reports on ordinary people caught up in the fighting in Syria. The human rights lawyer Philippe Sands looks back at his own family's history to make sense of crimes against humanity.