How was the "Miracle at Dunkirk" instrumental in the survival of the Allies and the final outcome of the war?

The Miracle at Dunkirk, formally called Operation Dynamo, was a military operation during World War II to evacuate British and French soldiers from the Dunkirk area of France. The operation took place from May 26 to June 4, 1940 and succeeded in evacuating 338,226 Allied soldiers.

The French and British forces had been cut off by the German offensive into Belgium, the Netherlands and France, but the German forces stopped the advance long enough for Allied soldiers to be lifted out of a fleet of about 900 small ships, which retained the fighting capability of the British Army, which was mostly in France. The evacuation method meant that the only material they could carry was limited to rifles and a few machine guns, so the army that landed at home in the United Kingdom was almost unarmed on arrival. Even so, this operation avoided an almost assured massacre of the British army, which allowed these men to later participate in the reconquest of France and Western Europe along with the Americans after the landing in Normandy.