"those who died for nothing"

Pardon?
If there was ever a force that needed to be stopped, it was the Nazis.
If there was ever a task that needed doing, it was the rescue of the 400,000 Allied troops who were trapped at Dunkirk.

Here we have a Canadian who played a vital role in the success of the evacuation... and your response is to post a simplistic history lesson and argue that servicemen like Clouston died for nothing?