Before two and a half hours ago, I thought the swastika was only in India and World War II. Then my art teacher put on a video about ancient Greek and Roman mosaics. In this video, I saw what was dubbed "Ancient Greek Swastica." I thought this an error and did a little research (I later found the link above). In no way is it only in India and World War II.
The Wikipedia article on it lists over a score of cultures with their own swastika with their own name to that culture. Among them are: Greek, Roman, Egypt, Native American, Japan, China, Celts, Aztec...
How do they all have their own version of a swastika relatively meaning a variance of the same thing in each?
I don't see how cross cultural contamination could have happened on this large of a scale. We know the Greeks/Romans knew of the Celts and Egyptians. Japan modeled their language on China's. The Romans traded with China. I can't be sure the Native Americans had contact with the Aztecs, but it is a possibility. And if this is a cross cultural contamination, where did it start?