I mean, the Persians and Greeks were once sworn enemies of one another, and now, thousands of years later, they get along with each other just fine. Many Persians or Iranians like the Greeks and vice versa, so why is it that the Chinese, Japanese and Koreans can't seem to do that with each other?

I mean, don't get me wrong--there's plenty of Chinese who get along well with both Japanese and Koreans and have Japanese and Korean friends and vice versa with Japanese and Koreans having Chinese friends, but the 3 nationalities have had a very tumultuous history.

Why can't the Chinese, Japanese and Korean governments simply put aside their differences and get along with each other like the Persians and Greeks did with each other?