The Canon: How War Came: The Immediate Origins of the Second World War, 1938-1939 by Donald Cameron Watt

My relationship with How War Came began in 1989. I was a wide-eyed history postgraduate at the University of Toronto. I enrolled in a course on the causes of the Second World War and our tutor told us that his former PhD supervisor had just published his magnum opus. I rushed out to buy a copy.

Although, of course, I knew how it would end, I still marvelled at how Watt kept me in a state of suspense as he told the story of European diplomacy from October 1938 to September 1939. The book moves at a heart-thumping pace, and the central characters are Europe's statesmen and diplomats. They are not introduced as the cliched one-dimensional appeasers versus anti-appeasers that still dominate views of the period, but as genuine flesh-and-blood personalities trying to cope with complex forces beyond their control.

"History is lived through and, for the fortunate, survived by people," Watt wrote. "Their actions, their failures to act, their hesitations, their perceptions, their judgements, their misunderstandings, misperceptions and mistakes act and interact upon each other across political, social and cultural divisions."

The two principal characters of How War Came are Neville Chamberlain and Adolf Hitler. And war came not because the prime minister encouraged the Nazi dictator by appeasing him, but because Hitler, cheated out of the small war he wanted against Czechoslovakia in 1938 by Chamberlain's diplomacy, was determined to have war in 1939.

Of Hitler's drive towards war, Watt concludes, "neither firmness nor appeasement, the piling up of more armaments, nor the demonstration of more determination would stop him".

Watt's book received the sort of acclaim that scholars dream of. Luminaries of diplomatic and military history - Paul Kennedy, John Gaddis and John Keegan among them - described it as a masterpiece. The New York Times hailed it as one of the best books of 1989, and it also won the prestigious Wolfson History Prize. Alan Bullock, the esteemed biographer of Hitler, declared that if one were to read only one book on the topic, this should be it.

In 1991, my relationship with the book turned into one with its author. I enrolled at the London School of Economics to write a PhD thesis about the war's origins under Watt's supervision. The first thing he said was that I should not treat his work, including How War Came, as canonical. With his encouragement and guidance, my scholarship matured and went its own way, but my admiration for How War Came only grew. It set the standard for multi-archival research and what it means to understand how international relations work.

I re-read it every now and again, and I often dip into it. Despite Watt's caveat, this book surely belongs in The Canon. It forever shattered the myth that international history is nothing but "what one clerk said to another" and it is - and I expect it will remain - the touchstone for anyone writing about the coming of war in 1939.