If we want to understand military strategy, we must first understand the strategist.

In THE STRATEGISTS, Professor Phillips Payson O'Brien delves deep into the psyches of five of the most impactful leaders in modern history - Churchill, Hitler, Stalin, Mussolini and Roosevelt - and their respective strategic methods and choices. Payson O'Brien shows how the views of these leaders were forged in World War One and the Russian Civil War, and that these views are crucial to understanding how they fought World War Two.

We see how, contrary to the prevailing view amongst contemporary historians, strategy in World War Two was highly individualistic and idiosyncratic. For example, Churchill's experiences of facing the German Army in France in 1916 made him unwilling to send masses of British soldiers back there in the 1940s, while Hitler's mistakes on the Eastern Front were influenced by his reluctance to accept that conditions had changed since his own time fighting in World War One.

This is a history in which leaders matter - for better or worse, the five leaders made their own choices, often ignoring external advice. The implications of the power of leaders remain with us to this day: to truly understand what is happening in Ukraine, for example, requires us to know what has influenced the leaders involved.