Their bigger problem back then, was the dealer was not local, and the silver and gold were siphoned oversea. East Indian Trading company was making all the money, then later during civil wars warlords were growing them to fund the war. So later on after the wars are over all drugs become banned and dealers / addicts who cannot kick it executed. It became a national security issue.Look into the Opium Wars in China in the 19th Century. Those are the reason China has strict laws against illicit drugs to this day.
Opium was a common part of patent medicines sold over the counter in the US and elsewhere then too. Lots of people then were addicted, including housewives. The stuff was even added to nostrums to help babies sleep, no kidding. :O During the World War I era the majority of those hard drugs were banned in the US and other countries because of the problems they caused then.
https://www.pri.org/stories/2019-08...rebels-now-you-re-invited-their-once-secret-0
Golden Triangle was a place where a warlord exile to, and use it to fund the insurgence. It sort of help fund some secret ops during Vietnam war as well. The biggest newspaper publisher in Hong Kong was once smuggling heroine between Golden Triangle / Pattaya / Hong Kong during Vietnam war and use the newspaper business to launder the profit.
Of course once the war is done these guys all got cut off and have to go legit.