Why did WW2 happen?

Hitler's war

“Hitler’s beliefs are absolutely paramount as a causal factor in the Second World War,” Richard Evans, the new Regius professor at Cambridge told me. “We know now through documentation that has become available over the last few years that he intended there to be a general European war really absolutely from the outset. He’s telling people in private in 1932, 1933, when he’s coming to power, that he’s going to have a general war.”

It’s a sentiment with which Sir Ian Kershaw, the world expert on Adolf Hitler, emphatically agrees: “The German expansion, as Hitler repeatedly said, could only come about through the sword – people weren’t going to give you this land back willy-nilly, so you had to take it. And that, therefore, was the underlying cause of the beginning of the Second World War in Europe”.

It’s largely thanks to recent research into the economic history of the Nazi state that we can now say without equivocation that this was Hitler’s war. Indeed, the scale of the German armament build-up during the 1930s, ordered directly by the German führer, almost defies belief. By 1938, for example, the Nazis were planning for the German air force to be larger than any previous air fleet in the world – larger even than the eventual size of the American air force at the end of WW2.

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The Nazi armament expansion plans would, according to the acclaimed economic historian Adam Tooze, “have consumed in terms of annual spending something like a third of German gross domestic product in peacetime, before the war had even started, whereas normal military expenditure would be something like two, three, four per cent of GDP. So this is tenfold what NATO, for instance, was demanding of its members in the 1970s and 1980s”.

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Hitler, according to Tooze, believed that, “War is essential to the health of the German nation and that Germany needs to break out of the encirclement that it’s in. So the idea that the Nazis could have somehow just extended the prosperity of the 1930s into some sort of peaceful VW future of modernity and satisfaction – well, it’s just not on the cards for Hitler’s regime. It’s a fundamental misunderstanding that many people succumb to, but it’s really not what’s on Hitler’s mind at all.”

Instead, what was on Hitler’s mind was struggle – an epic racial struggle. “He isn’t a statesman in the normal sense of the word,” says Tooze, “making straightforwardly rational calculations, assuming always that there will be a high probability of ultimate success. This is a man for whom politics is drama, a tragic drama that may not have a happy end. And so he is willing to take risks that he thinks are inescapable even if the odds are very highly stacked against Germany.”

The aggrieved Germans post-WW1

But, of course, as Richard Overy emphasised to me, we mustn’t completely run away with the idea that Hitler was the only reason the war happened. The underlying, long-term cause of the conflict was a settlement at the end of the First World War which left Germans deeply aggrieved, both at the loss of their territory and the massive reparations the Allies demanded. This, as Overy makes clear, “distorted the international order” and in turn was a crucial factor in making Hitler’s subsequent electoral success possible.

“The important thing,” says Overy, “is identifying why Britain and France go to war. And I think there is a complex set of answers there. I think partly the answer is genuinely that in Britain and France (and in Britain in particular) both the elite – but quite a large part, I think, of the [general] population too – saw themselves as having some kind of responsibility. This wasn’t only responsibilities as the sort of ‘masters of empire’, but responsibility for maintaining the stability of the world order and a world order which, despite their imperialism, represented western values.”

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By the late 1930s Hitler was careful to hide one issue – his desire for a war of conquest in eastern Europe, which would seize the rich agricultural land of the Ukraine as part of a German empire – behind another: the recovery of German territory lost as a result of the Treaty of Versailles at the end of the First World War. There was clear public support in Germany for the second aim, but much less so for the first.

Indeed, many in the British establishment in the 1930s felt that somehow Germany had been treated ‘badly’ at the end of the First World War – but these same people would have been appalled at the notion that what Hitler really wanted was not for the German speaking regions of eastern Europe to be incorporated once more into the Reich, but instead to create a massive eastern empire, stretching all the way to the Urals and based on slavery.

And the moment at which the British realised Hitler had been misleading them came in March 1939 when the Germans invaded the remaining Czech lands – territory that had not been given to them as a result of the Munich agreement the year before. The entry of the Nazis into Prague demonstrated to the British, says Richard Evans, that Hitler “did not just want to incorporate ethnic Germans into the Reich or to right the wrongs of the Treaty of Versailles – he was actually going for something much bigger.”

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Why did Britain help Poland?

Shortly after the German takeover of the Czech lands, Neville Chamberlain offered a guarantee to the Polish that if they fell victim to German aggression then the British would, as he put it, “inevitably be drawn” into the subsequent “conflagration”.

And the reason that the British chose to make a stand over Poland, was, it appears, just because they thought that this country was next on Hitler’s wish list. “It’s simply a strategic evaluation,” says Anita Prazmowska, who teaches at the LSE, “this realisation that the balance of power in Europe is tipping dangerously against British interests and it could be dangerous – you’ve got to do something about it.”

Hitler knew the odds were stacked against his own country – and yet still wanted violent conflict

According to Professor Prazmowska, the British decision to offer a guarantee to the Poles had no ideological dimension – it was straightforward, pragmatic politics. “Far from this being a carefully calculated policy, it is a policy where Chamberlain, with a very weak foreign secretary, Lord Halifax, finally says let’s do something. It’s very badly thought out, because war is declared knowing full well you’re not going to defend Poland… So indeed it is not a fight for Poland, it is actually an attempt to indicate to Germany the unacceptability of her behaviour.”

• Read more about the 1939 invasion of Poland

One can still argue backwards and forwards, of course, about the relative competence of Chamberlain at Munich and subsequently over the question of the Polish guarantee, but, ultimately, all of this debate comes back to Hitler, because he was the key driver of events. And the truth is that he was driven not by rational argument but by fervent ideological belief. As Tooze says, he went to war “because he’s convinced, in my view, that the world Jewish conspiracy has taken on a whole new ominous character, and this starts in the summer of 1938, I think, fundamentally with the Evian Conference in which America becomes involved in European affairs around the issue of the organised emigration of eastern European Jews”.

So by 1939 Hitler had come to believe that “the real centre of the world Jewish conspiracy is Washington and Wall Street and Hollywood, and that, of course, fundamentally shifts your assessment of the strategic picture, because behind Britain and France, as in the First World War, ultimately stands the force, the full force, of the American armaments economy. And so with that in mind the balance of force in Europe in 1939 looks extremely ominous, because British rearmament is beginning with real intensity from the beginning of 1939. The Germans understand this, and so even though the situation is bad in the autumn of 1939 they quite rightly predict that it’ll become worse in 1940, 41, 42, and this is because they’ve come face to face again with the limitations of their own economy.”

• How was Germany able to afford the astronomical cost of rearmament in the 1930s?

Furthermore, Hitler goes to war not knowing “how this struggle is going to end”. On this interpretation – and I certainly find it persuasive – Hitler stands revealed as one of the least “normal and predictable” politicians in world history. Indeed, on the contrary, he was someone who knew that the odds were stacked against his own country – and yet still wanted violent conflict. Someone prepared to gamble the future lives of millions of his people on the chance that the Germans could win a swift, decisive war. Someone who believed with all his heart in a deeply pessimistic view of the human spirit. “The earth continues to go around,” he once said, “whether it’s the man who kills the tiger or the tiger who eats the man.”

And while all this is a million miles from AJP Taylor’s assessment that Hitler was a politician the west could have dealt with, it is certainly true that the German leader would have preferred to have his war of European conquest without the involvement of the British in the fight. “What a terrible disaster the war was for both our countries!” a former SS officer once said to me, just before I filmed an interview with him for the documentary series I made 18 years ago, Nazis: A Warning from History. “As a result of us fighting together you [the British] lost your empire and our country was beaten and divided. If only we had been partners we could have ruled the world together!”

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Such a partnership was a fantasy, of course. Not only could Britain never have stood by and seen Hitler enslave mainland Europe, but it was obvious by the spring of 1939 that the Nazis could not be trusted to keep to any agreement they signed. As Herman Göring said after the war, treaties between states were “so much toilet paper”.

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So Hitler emerges, surely without question now, as the person most responsible for the war. And the fact that such a dark figure – ideologically driven to the point of taking foolhardy risks – exercised such control in 1939 over the destiny of both Germany and the rest of Europe must, even now, 80 years later, be a warning for us all. It doesn’t take much imagination to think what the fate of the world would have been had he possessed nuclear weapons. Indeed, what a study of this subject has led me to believe is that on 30 April 1945, when Hitler finally realised the game was up and held a revolver to his head, if he had actually had the power, he would have blown the whole world apart along with his brains.

Laurence Rees is a filmmaker, author and former head of history at the BBC

This article was first published in the September 2009 issue of BBC History Magazine