I used to think that prior to the Nazis it was only an asian thing, but then I learned that it's been in Europe as well for a long time. So now I'm curious to learn how this might have affected the Nazi decision for this symbol.
You'll likwlt find this old response to be of interest. The sum of it is that the Swastika was already established as völkisch political groups in Germany, who associated it with the (the pseudo-ethnic group) Aryans, that is to say, Europeans, to get to the heart of your question.