An excerpt:
"...The trade in opium, often grown in India, boomed in China despite efforts to ban it with large amounts of the drugs being shipped into the country by British merchants.
Attempts by the Chinese government to disrupt the trade were met with force and Britain twice went to war to protect its stranglehold on the market and expand its reach into a country which had been closed off to western influence.
British merchants forced the Chinese to grant them access to Chinese ports and won the right for their citizens to be exempt from Chinese law.
Mr Fenby said: "The unequal treaties, as they became known, caused a great deal of resentment in late 19th century and 20th century China among Chinese nationalists.
"They would inveigh against the foreigners who came in and spread opium in China and the presence of the foreigners was blamed for the bad state China was in. ...."
"China has a zero tolerance policy towards drug smugglers, whether Chinese or foreign."
http://www.telegraph.co.uk/news/worldnews/asia/china/6908467/Akmal-Shaikh-China-refers-to-controversial-Opium-Wars-with-Britain.html
ยอดผลิตแยกตามประเทศ
http://www.justice.gov/ndic/pubs11/18862/heroin.htm
