On May 10, 1940, Neville Chamberlain reluctantly stepped down as prime minister of Britain and handed the keys for 10 Downing Street to Winston Churchill.

In the early hours of the same morning, Adolf Hitler’s special train pulled in at a small German town near Aachen close to the Belgian frontier. The dictator and his military staff had come to witness the launch of the German army’s offensive against France by slicing through Belgium and Holland.

In the triumphal afterglow of VE Day on May 8, 1945 — its 65th anniversary commemorated last week in Europe — it is now barely remembered and rarely discussed how perilously close Britain came five years earlier to negotiating an end to the war with Germany.

The swift disintegration of the much-vaunted French army, and the encirclement of the British Expeditionary Forces pushed to the Channel ports by the German military from south and west, left Britain alone and exposed.

Hitler had read the temperament of Britain’s ruling elite carefully. Chamberlain was only the last of the apostles of the appeasement policy that gave Hitler time to rebuild Germany and launch a military machine the likes of which had not been seen before.

Churchill was vilified by his peers for warning the world of Hitler’s demonic ambitions. Distrust of Churchill reflected Britain’s mood during the 1930s.

There was anti-war and pro-German sympathy that reached upwards into the royal family, senior civil servants, parliamentarians and intellectuals who believed the 1919 Treaty of Versailles had treated Germany unfairly. David Lloyd George, Britain’s prime minister during the First World War, after meeting with Hitler in 1936, called him “the greatest living German.”

Then there was Joseph P. Kennedy, U.S. President Franklin Roosevelt’s ambassador in London, who disliked Churchill and was not alone in viewing Nazi Germany as a bulwark against Communist Russia in the east.

The last few days in May 1940 were decisive. Lord Halifax, the foreign secretary and member of the War Cabinet, wanted to know if Churchill would consider any peace term from Hitler as he leaned in that direction.

Events moved swiftly as France was pushed to surrender. More than quarter of a million British soldiers were trapped around Dunkirk and needed rescuing, or they would become prisoners. A massive ferry operation surprisingly succeeded in bringing most of them safely across the Channel raising British morale under precarious circumstances.

Stalin’s Russia had signed a non-aggression pact with Hitler’s Germany in August 1939, and the U.S. in an isolationist mood remained distant. Mussolini’s Italy was about to make common cause with Hitler, and Franco’s Spain, though neutral, looked favourably towards Germany as did Japan. Yet Churchill stood defiant with Britain, alone in facing Hitler’s army.

On May 26, a desperate Paul Reynaud, France’s prime minister before Paris fell, visited London and Churchill told him, “We would rather go down fighting than be enslaved to Germany.”

Churchill’s indomitable spirit rallied Britain 70 years ago in defending, as he mentioned in his speech to Parliament on June 4, 1940, “the world cause to which we have vowed ourselves.” And it was certainly providential freedom found in Churchill its most determined defender at that perilous moment in world history.