Question

If Germany had been more successful in the Battle of the Atlantic, what would have happened?

Answer 1

It's possible that England could have been starved out of the war. As an island nation, England was highly dependent on imports to stock its shelves, fill its factories with raw materials, and to basically keep on fighting with whatever the US and its allies could bring in past the German U-boats.

If England was knocked out of the war by Germany's blockade attempts, especially if they had followed through with a successful invasion via Operation Sea Lion afterwards, then the Allies would have lost a key strategic ally potentially ceding the fate of Europe to the Third Reich.