Will the "Dunkirk" movie be any good? I cannot say that I am optimistic. But if you want to understand the bigger picture, here is my take on it:
From: My Very Short Take on World War II... http://www.bradford-delong.com/2017/01/my-very-short-take-on-world-war-ii-hoisted-from-the-archives.html: How are we to understand World War II? One way is to take a look at the first three major campaigns—the Polish campaign of September 1939, the French campaign of May-June 1940, and the first six months of the Russian campaign from June 22 to the end of 1941.
In the 1939 Polish campaign, the Nazis lost 40,000 soldiers killed and wounded. The Poles lost 200,000 killed and wounded. The Poles also lost about 1,000,000 taken prisoner.
In the 1940 French campaign, the Nazis lost 160,000 soldiers killed and wounded. The allies lost 360,000 soldiers killed and wounded. And the allies also lost 2,000,000 soldiers taken prisoner.