The Opium Wars between China and the British Empire were a result of China's attempt to shut down the opium trade.

https://www.britannica.com/topic/Opium-Wars

Hong Kong is a geopolitical football because the Mayor of Hong Kong tried to stop a foreign corporation from getting their citizens addicted to drugs.

In accordance with British commercial law, the foreign corporation returned with the British Navy and took it over. And then kept pushing the drugs successfully.

Search for the opium wars, fascinating (and terrifying) stuff.