Darkest Hour - 1940

The film, Darkest Hour, presents the dangerous time for Western Europe, and especially for England, after the Germans defeated France.  Not only was nearly the entire British Army exposed on the breaches of Dunkirk, but the Nazi war machine seemed unstoppable. 

British appeasement policies in 1938 seemed to avoid war, at the expense of Czechoslovakia; however, it merely emboldened Hitler to proceed with plans to attack Poland in September 1939.

Churchill ( played by Gary Oldman in the film) had been a lone voice warning against Hitler and German plans to bring war to Europe once again.  After the attack on Poland, and the German invasion of France, Churchill was elevated to Prime Minister. 

When France surrendered Britain pulled off a near-miracle and rescued over 300,000 soldiers from Dunkirk.  They lost all their equipment - tanks, guns, etc - but at least the army was intact to oppose the expected invasion of Britain.

With pressure mounting to make a deal with Hitler to avoid an invasion, Churchill instead made his famous "we shall never surrender" speech in June 1940 (depicted in the film).  From the point of view of Americans his most stirring line might have been that  Britain would fight on until "the New World with all its power and might came to the rescue and liberation of the Old". 

Of course, US entry into WWII would not occur for 18 more months with the attack by Japan (Germany's Axis ally) on Pearl Harbor.  It often surprises people to learn that by the time that we entered the war, the Axis powers were winning everywhere.  The Allies were losing the war.

But Britain held fast, and the Royal Air Force battled the Germans successfully for control of the air.
Instead of invading England, Hitler made the fateful decision to, instead, turn east and attack the Soviet Union.