HIstórias dos Impérios: "A Guerra do [pelo] Opium"
In the eighteenth century the company controlled the opium-producing areas in India and had a dominant position in the trade of Indian opium into China.
The profits helped subsidize British control of India and to keep exports to China balanced with imports.
In the late 1830s the British government started the First Opium War by sending a naval expedition that easily defeated Chinese forces, opened up Chinese ports to British trade, and won monetary compensation and Hong Kong as a British colony from China.
The Second Opium War began in 1856 when Britain, France, Russia, and the United States attacked China in order to gain increased access to Chinese markets and to legalize opium in China.
The Emperor was forced to pay the British government £20,000 which was
according to Abadinsky (2001) “more than enough to offset the balance of trade which was the real cause of the war” (page 29)." Recreational Drug Prohibitions by Mark Thornton (Mises Institute; Auburn University) 8/31/2006