The idea that the Second World War had a ‘turning point’ or ‘turning points’ has become a historians’ parlour game. But what exactly does it mean? Few other major events have attracted the same curiosity. A turning point in the French Revolution? The Crusades? The suffragette movement? It is possible to identify continuities and discontinuities; to search out periods of accelerated change; to reflect on the narrative as a complex process of interaction between historical actors and historical context, between individual initiative and the contingent pressures that limit or advance it. But a turning point?

With the Second World War the idea of a turning point raises more questions than it answers. Some favourites – the Battle of Britain; the German halt at Moscow in 1941 – seem to come too early for a war destined to last another four or five years. Most of