During the Battle of Dunkirk in 1940, German forces successfully cut off several units of British, French and Canadian troops from supporting forces and supplies. Nearly 350,000 Allied troops were left stranded on the beaches and harbor of Dunkirk, in France, amounting to what Winston Churchill called "the whole root, core, and brain of the British Army." Between May 26 and June 4, 1940, in what was named Operation Dynamo, a total of 338,226 soldiers...