Chinese scientists, conducting genetic research in western China, recently tested the people in an ancient, and remote, village, and found that the DNA of the villagers was 56 percent Caucasian (Indo-European). The current theory is that these people are descendants of Roman soldiers who were long rumored to have established an outpost on this eastern end of the ancient Silk Road (the caravan route from China to the Middle East.) The Chinese are not happy with findings like this.
The Chinese government has long been uneasy about archeologists and anthropologists finding evidence of European peoples living, and settling, in western China thousands of years ago. The Chinese have a high opinion of themselves (often justified), but because of the European role in humiliating China in the 18th and 19th centuries, they are uncomfortable with the idea that the damn Europeans have been in their neighborhood even earlier. Earlier discoveries included very old (more than 3,000 years ago) burial sites containing tall, blonde, warriors. There was also a village of ancient Jews in western China, where the people had only stopped practicing Jewish religious rituals in the last century.
What all this is about is the Indo-Aryan tribes that occupied the Eurasian plains after the last Cold Age ended 12,000 years ago. These guys domesticated horses and ranged east, south and west, attacking anyone they met. This had profound implications for the later development of Eurasian cultures.
Three thousand years ago, the Dravidian civilization, centered along the Indus river, was conquered by Indo-Aryan tribes, rolling out of Central Asia aboard chariots and armed with iron weapons. These aggressive interlopers also brought with them a language (Sanskrit) and religion that developed into modern day Hindi and Hinduism (plus Buddhism, Sikhism and many others you rarely hear about.)
Other Indo-Aryan tribes went into Iran (their descendants are still there) and Europe (ditto). Some went east, but not to the Pacific. They encountered the ancestors of the Huns, Mongols, Turks and other East Asian nomadic tribes, who spent most of their time attacking the settled populations to the south (mainly China). The Chinese may be unhappy simply because they have to give the "northern barbarians" credit for driving the Indo-Aryan tribes away, rather than letting Chinese soldiers do it. Thus its currently a big deal in China anytime Chinese technology, or diplomats, beats the Westerners. In the Chinese universe, it's the supreme insult for foreigners to best the Chinese, militarily or otherwise. But for the last few centuries, that is what happened. China isn't really looking for a war with the West, but politicians find it easy to win approval by playing up the might of the motherland, and what China can do (in theory) if anyone messes with us. That process induces some amnesia about what has really happened in the past, but that's what nationalism and demagoguery are all about.