I recently ended up living in Melbourne which I would easily estimate to have around 30% of the city population coming from various parts of Asia, and got to say that I don't have too much trouble telling the Chinese and Japanese apart (too few Koreans around), despite that the other countries I've lived in have had very few peeps of those nationalities for me to judge beforehand.

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You know the world is going crazy when the best rapper is a white guy, the best golfer is a black guy,the tallest guy in the NBA is Chinese, the Swiss hold the America’s Cup, France is accusing the U.S. of arrogance, Germany doesn’t want to go to war, and the three most powerful men in America are named Bush, Dick, and Colon.
— Chris Rock