Fifty years ago Bomber Command launched a massive campaign against Nazi Germany - the Battle of the Ruhr. In this special edition Jonathan Dimbleby explores the military and moral issues posed by a form of warfare which, since the end of the war, has become a matter of great contention. Was Britain's area-bombing campaign a necessary strategy to defeat Hitler or was it a war crime? The film revisits the industrial city of Essen to hear from Germans who endured the unceasing night-time campaign and, in the studio, Dimbleby questions RAF veterans, victims of the bombing, military historians and those recently involved in policy-making.