The Opium Wars & Drug Legalization

MercatorNet has an excellent article outlining the history of the Chinese Opium Wars. What I want to focus on here is the last stage of the history. Due to the Treaty of Tientsin in 1858, China was forced to legalize the importation of opium which eventually led to the domestic production of the drug. Here is the result:

The prevalence of opium consumption in China skyrocketed in the 19th century,
from about 3 million opium smokers in the 1830s, to 15 million opium addicts by
1890, or about 3 percent of the population at the time. According to the Chinese
delegation to the International Opium Commission of Shanghai (1909), this
increased to about 21.5 million by 1906. Others put the number close to 40
million people in 1890, or about 10 percent of the population, growing to
unknown levels from there. According to official Chinese figures, opium
consumption affected 23.3 percent of the male adult population and 3.5 percent
of the female adult population of China in 1906. Other estimates ranged from 13
percent to 27 percent for the male adult population of the country. By any
estimate, China was consuming between 85 percent and 95 percent of global opium
supply at the beginning of the 20th century. Never before or since has the world
known a drug problem of this scale and intensity.

Drug Legalization led to a proliferation in its use. This seems to be a rather obvious fact and a reader might wonder why the author chose to belabor the point with so many statistics. It might be because this obvious fact is not so obvious to many today. I have come across several people who deny this claim, though it seems self-evident to me.