Dunkirk evacuation

I was reading about the movie Dunkirk at the IMDB here; http://ift.tt/2onG1gp
One of the trivia items reads;

Quote:

The evacuation is often seen as a terrible defeat for the British as it resulted in them continuing a war that destroyed their empire and turned the UK into an American satellite.

What does this mean? What if the British army been destroyed on the beach by the Germans. Would this have kept them out of the war with Germany taking over Europe and possibly Asia while allowing the British Empire to continue to exist as it did before?

What am I missing from this line of reasoning?

Ranb

via International Skeptics Forum http://ift.tt/2oqTaaq