This has not only shown Prince Harry's exceedingly poor taste (but remember, he's a 19 year old student), but will also offend many of both sides of the North Sea.
I can imagine the reaction for many modern Germans, (particularly those descended from Anglo-German aristocracy) will be outrage too. After all, associating a German with Nazi-ism is something our British press are good at and will be hugely offensive to the vast majority of Germans who see us as living in the past.
However, I cannot see the point of the original post?
Put it this way Asian1, my own surname originates from Koblenz as I can trace my ancestry back to German immigrants to the UK in at the end of the 19th Century. My own paternal grandfather fought at the Somme for the British, and there's evidence to suggest that he had first or second cousins fighting for the Kaiser. Would it make it more or less offensive if I were to turn up at a fancy dress do in an Afrika Corps uniform given my ancestry?