Not bullying neighboring countries is closely related to China's long-term weakness and failure to recover its national strength in modern times. Especially after 1840, the Qing Dynasty lost the Opium War. After that, China was invaded by western powers and Japanese all the year round, and it was not until 1949 that it gradually resisted foreign invasion.

However, in ancient times, China became stronger and bullied its neighbors. Since the Han Dynasty, China's wars with Vietnam and Korea have lasted 1000 years. Vietnam and most of the Korean peninsula were once colonies of China. Today's Gansu, Inner Mongolia and other places have not been the territory of China since ancient times, but were seized by the Han Dynasty to destroy the Huns. The Tang Dynasty was even more outrageous, sending troops to Kazakhstan, Afghanistan and other countries in Central Asia and to Lake Baikal in Russia. But also incorporated Tibet into Chinese territory. In the Qing Dynasty, China entered the last period of historical expansion, and once occupied Myanmar, Central Asia, Outer Mongolia, Outer Manchuria, Tangnu Liang Hai and other areas that do not belong to China now.

China doesn't bully other countries now because its national strength is insufficient, which is related to the dominance of the United States and the strong environment of its neighboring countries. It only has a certain relationship with the doctrine of the mean. And if China is strong, it may continue to expand its territory like Emperor Wu of the Han Dynasty. (at least recover lost ground)