20th Century vs Viet Nam 1979 USSR 1969 (?) border fracas India 1961 (?) border fracas Tibet 1950s reoccupation of old Imperial claim Korea 1950-53 vs US/UN Japan 1937 - 1945 Nineteenth Century vs Japan 1895 over control of Korea Several expiditions to retain control over Imperial claims on non ethnic Chinese territories, such as Tibet. Mostly Chinas warfare in the 19th Century was several bloodly & long running internal rebellions, such as the Taiping. Plus they tried to fight the European imperialists. The rebellions were motivated by corrupt Ching (Manchu) dynasty administration, and a deteriorating economy. The Taipings appeared to be incorporating some of the socialist ideas that were circulating amoung European revolutionarys in the 19th Century. To find aggresive Chinese military action you have to go back to the Ming dynasty, when many expiditions were mounted against the neighboring states to reestablish their status as vassals to the Middle Kingdom. The Ching or Manchu dynasty did the same, sending out armys to establish dominance over the neighbors & collect tribute. But technically the Ming was not a 'Chinese' dynasty but rather the rulers at the top were Manchurians. The same for the Mongols. But in both cases the rulers adopted many Chinese habits after a few generations. If you go back to the original unifiying 'Chin' dynasty you can trace a sucession of imperial expansions by sucessive dynastys. Each fell apart eventually. The successor dynastys conquests usually included non Chinese states. Viet Nam is actually a Chinese state that broke away. The language & culture are very closely related to the southern Chinese. During the same era as the Roman empire the Chinese had been expanding into the coastal region of southern China and settled the Red River Delta (site of modern Hanoi), getting rid of the natives much as the Europeans did in America. Later during one of the periods of Imperial dissolution, approximatly 1100 AD on the Christian calendar the Viet revolted and made themselves independant. Although the subsequent imperial Chinese governments and Emperors were able to regard Viet Nam as a vassal state they never actually conquored it again. The Mongols did occupy the Red River Delta for a while. This accelerated the migration of the Viet south along the coast where they were replacing the native people. Mostly Khmer I think? the Vietnamese ruler moved his capitol south out of reach of the Mongols as well.