As long as they are made to understand the nature of the twin lightning bolt symbol in relation to American history and the Marine Corps' own brave contributions to keeping America free from tyranny, I think they will be properly chastened.
I sometimes forget that I am now of an older generation for whom Nazism and its symbols were of far more recent vintage when I was a young man. Those of us who were born in the '40s and '50s knew those symbols implicitly as well as what they represented. When I was a kid and we played war games (with actual toy guns, Heaven forbid!), we often pretended to fight the Germans and Japanese, as our fathers had.