Britain's history, but....they were never in danger. I'm not saying they didn't know that. The story is still amazing and the citizen navy still heroic, but Hitler never had any intention to overtake them. He would have let them be rescued regardless.

It's an interesting study and a sensitive topic as it's remembered as such a heroic day.

Hitler still wanted to be friendly towards England. He still thought he could win them over as there were those in England pushing for alliance. He wanted them to concede to him with their empire intact. There were actually a lot of people in England pushing for some sort of alliance with Germany to avoid complete destruction and Hitler thought it was worth letting the troops go to advance that cause and see if he could still win over the English. It was a risk he was willing to take to get the empire intact. Of course it didn't play out as he hoped, but those soldiers didn't worry him. It was the US that was going to make the difference in Europe, not those trapped at Dunkirk.