The United States' Prohibition gave rise to the most powerful gang in their country because they changed the trade form, forcing alcohol transactions underground. This initially led to deteriorating public security, and not only did the country lose tax revenue, but those reckless gangs grew right where they were.
Of course, this was closely related to the weak control and measures of the federal government at the time, but ultimately, it was about demand...
Just like how the United States consumes one-third of the world's drugs every year now, it's the strong demand that makes drug trade impossible to ban, rather than the drug dealers from Mexico being truly invincible.
Mountain Eagle definitely wouldn't touch drugs, but he himself is from a trade background. He not only knows how to conduct legitimate trade, but also knows how to engage in transshipment trade and gray trade.
