Why History Is Important
When my younger brother was working in Hong Kong, my Mother went for a visit. She noted when she returned that everyone was very polite to you, unless you were Japanese. She couldn't understand why the Chinese, Philippinos, Koreans, etc. were all very rude to Japanese tourists.
I gave her a list of movies to watch and told her that not everything they contained was World War II propaganda.
The Japanese have been changing their history books again. While emphasizing their "victim status" as the only nation that had been attacked with nuclear weapons, they have been softening the actions of the Japanese forces to the level of "fraternity hazing".
You have to accept if you have interacted with Asians in their home countries that they all have some level of racism in their cultures. This can lead to some tense situations for the average American who can't pick up the differences between people from the different national groups.
The Chinese are reacting to this new textbook with anti-Japanese rallies
. These rallies have government sanction or they wouldn't be occurring. The Chinese Communist Party got its real start fighting the Japanese in World War II, so this is important to Party officials.
Americans tend to move on and forget about things as a whole, but much of the world is like a few Southerners who simply won't let things lie and get on with their lives.
You should learn from history, not stew in it. Find out what really happened, accept the bad with the good, and don't start walking down the path that resulted in the bad.