Legalizing recreational drugs may help, but it won't solve the problem; hard drugs are still a thing, the cocaine trade is booming (read an article that the amount of cocaine intercepted in the Rotterdam port has gone up 10x in the past three years, and that's just the stuff they catch; wouldn't be surprised if that represents only 10% of what comes in. The article mentioned that the interception doesn't seem to have any effect on the 'street price').

If for example the US manages to somehow curb the drug crisis, they'll find other buyers easily. Or switch to other products in demand, like insulin.