Escape from Dunkirk: Hitler's four strategic mistakes

75 years ago this week, the British army stood on the brink of disaster. Routed by the Nazi blitzkrieg, and facing annihilation in a town in Northern France, most of the troops escaped in what some called a miracle.

Within days, a "colossal military disaster" (in the words of Lord Gort, Commander of that army) had somehow been turned by the British into a glorious symbol of resistance and their indomitable island nation. Indeed, the term "Dunkirk spirit" is still used to describe a collective pulling together in the face of adversity.

Dunkirk represented the first of four massive strategic errors of judgment by Hitler. Two were committed in 1940, and involved Germany failing to finish off the British when they were down and effectively alone. The second two mistakes, even more significant in global terms, took place in 1941 and ensured Hitler's eventual defeat as he brought first the USSR and then the USA into the war on Britain's side.

As their French, Dutch and Belgian allies collapsed before the German onslaught, the survivors of the British Expeditionary Force retreated to the channel port of Dunkirk. With their backs to the sea and on the brink of obliteration by the vastly superior Luftwaffe and Wehrmacht, the British were saved by what must be the most remarkable evacuation of modern times. In "Operation Dynamo", the Royal Navy – assisted by hundreds of private fishing boats, life-boats and yachts from England (200 of which were sunk by German air attacks) – ferried to safety a third of a million British and French soldiers.

But for all the heroism on display in the Channel that week, equally important was a bizarre decision by Hitler to halt his Panzer divisions for 36 hours, instead of letting them finish off the exhausted and outnumbered British. He explained to his generals why he had held them back: "it's always good to let a broken army return home to show the civilian population what a beating they've had". If this was part of his reasoning, it was an epic misjudgment of his opponent's national psyche.

Had all the British soldiers at Dunkirk been killed or captured, the nation would have been utterly traumatized, and it is hard to imagine that the British have been able to resist for long. As it was, the troops returned home to a rapturous reception.

"Wars are not won by evacuation; but there was victory inside this deliverance." So declared Prime Minister Winston Churchill to Parliament, before uttering his most phrases about defending our island, fighting on the beaches, and never surrendering. The Dunkirk evacuees formed the core of the British army that went on to defeat the Germans in North Africa and later – with American and other allies – returned to the European continent on D-Day in 1944.

Hitler's second mistake occurred three months later, in August 1940. Vast waves of aircraft were launched to achieve German air superiority over England. But with the Royal Air Force again outnumbered, and its losses mounting dangerously, Hitler suddenly instructed the Luftwaffe to shift bombing targets away from the airfields of the beleaguered RAF to London and other cities. So at this pivotal moment, RAF Fighter Command was granted time to recover and regroup, allowing its pilots to continue their heroic defence, and the Battle of Britain was won.

Again, Hitler had psychologically misread his opponents. In switching his attacks away from the airfields, he assumed that incinerating thousands of civilians in the cities would cause British morale to surrender. But the actual British response was epitomized when Churchill went to visit the bombed-out working class areas of East London: "It was good of you to come Winnie," the crowd shouted. "Give it 'em back, we can take it!"

If they could not control the skies, the Germans would be unable to ship their invasion force across the Channel without being sunk by the Royal Navy. Britain was therefore saved - for the time being - but for the next eight months it faced the Nazi war machine alone. Despite warnings from Churchill and others that the Germans intended to invade the USSR, Stalin continued to believe Hitler was a sincere ally.

Meanwhile, across the Atlantic, there was little desire to join the European war. The US Administration of President Franklin Roosevelt faced an assorted group of Republican isolationists (such as Senator Taft of Ohio); Democrat appeasers and defeatists (Ambassador Joe Kennedy); pro-German sympathizers (the celebrity aviator Charles Lindbergh); anti-semitic industrialists (Henry Ford), and sections of the Irish-American, German-American and Italian-American communities. All of these bitterly opposed FDR's efforts to support the desperate British and preserve the world from a comprehensive Nazi victory.

Earlier that summer, Churchill had declared that "Hitler knows he will have to break us in this island or lose the war." But Churchill was only half right. Right in the sense that, without breaking the British, Hitler was indeed going to lose eventually. But wrong that Hitler fully knew it. By September 1940, facing a reconstituted British army (thanks to Dunkirk), British control over its own skies (thanks to the Battle of Britain), and mastery of the seas (thanks to the Royal Navy), Hitler realized that he could not launch what would have been the first successful invasion of England since 1066. And he turned his attention elsewhere.

Hitler's third strategic mistake was rooted in his deep loathing of both Communism and the "Slavic races" that formed the USSR. Frustrated that his lesser foe to the west was unvanquished, he persuaded himself that the Nazi conquest of Russia would cause Britain to surrender anyway. "Barbarossa" was launched in July 1941, unleashing the largest invasion force in history, with 4 over million soldiers. Within months, the Germans had lost hundreds of thousands of men - and murdered millions themselves, mostly Red Army prisoners of war and Jewish civilians.

The fourth error committed by Hitler was his declaration of war against the United States after the Japanese attack on Pearl Harbor in December 1941. On hearing the news, Churchill said he "went to bed and slept the sleep of the saved and thankful". It was poetic, but premature. After all, the Japanese attack indeed ensured that the US would go to war – but only against Japan.

Without Hitler's wholly gratuitous declaration, the Roosevelt Administration would never have persuaded Congress to go to war in Europe instead of focusing on the Pacific. And without US involvement, and knowing that the British could never have launched a D-Day type invasion on their own, the Germans could have kept a far smaller presence in France, which would thereby have allowed them to concentrate overwhelmingly on defeating the USSR. Once Hitler was forced to engage in monumental struggles for existence on both his eastern and western fronts simultaneously, the end was never really in doubt.

Churchill was surely right to declare that 1940 was the British people's "finest hour", as they resisted the Nazis alone. But key to British success and survival were the four unforced errors committed by the Fuehrer. Had any one of those decisions gone the other way, the result would have been very different, indeed catastrophic.

His fatal and perennial misjudgment is the one thing about Hitler anyone has to be grateful for. As the British justly celebrate the extraordinary evacuation of their troops from Dunkirk thanks to the motley but heroic motley flotilla 75 years ago, they should also recall that over-arching piece of good fortune which helped ensure their survival – and thereby that of the free world.

(Andrew Gilmour is the director of Political, Peace-keeping, Humanitarian and Human Rights in the Office of the United Nations Secretary-General. He wrote this essay in his personal capacity.)