It is commonly said that China has made no attempt to exapnd its territory for many centuries – commonly said but incorrect. The Qing Dynasty saw a number of attempts.
The idea that the Chinese state wishes to expand its territory has received a great deal of attention over the years, especially recently as its phenomenal economic growth has raised it to the status of a potential superpower. Chinese scholars have frequently stated that there has been no expansion of Chinese territories for centuries and not since the Mongol Conquerors of the Yuan Dynasty have new lands been brought under Chinese control. Indeed, for more than one thousand years, the extent of Chinese territory has remained essentially stable in terms of extent and scope. Particularly with respect to southwards expansion, it is said, China has not increased its reach since the Tang Dynasty and the one thousand year long colonization of Vietnam has never been repeated. This is true in some senses but not entirely true in another. For example, the Mongols were defeated by the Vietnamese at the three battles of Dac Banh, thanks to their ability to seal of the harbour with chains and stakes and commence a form of early guerrilla warfare. Yet this has not been the only attempt to move southwards in one form or another.
Historically, the relation with states on the southern border has led to the permanent occupation of the lands once known as Yueh Nam, the resistance of Dai Viet (Vietnam), the incorporation in the seventeenth century of Yunnan and of the twentieth century of Tibet (it is possible to debate the dates at which these conquests effectively occurred). However, among these thrusts, there have been numerous attempts to conquer land which have ended in failure. One such effort was the Qing attempt to conquer Myanmar (Burma) launched by the campaign of 1765-70. This has come to be accepted as the most disastrous military campaign launched by the Qing Dynasty – the Chinese army has, in truth, a very long history of failures and disasters (all military forces do). Failures are generally hushed up while successes, however, partial, are generally praised beyond their real meaning.
In the case of this campaign, the Chinese troops fell afoul of the relentless problems of the terrain and, above all, the disease endemic in the region. Few troops can attack an alien jungle without massive losses from disease and various types of misery and the Qing troops proved this once again. With enormous loss of life, the Chinese withdrew from their attempt at conquest, which was based either on conquest for its own sake/desire to punish recalcitrant Burmese royalty/desire to control important mineral and human resources, according to taste.
These days, after the isolationism of the Mao Zedong era, Chinese officials will look to economic rather than military power to dominate its resource-rich but politically-useless southern neighbour.