Corruption followed by Drugs. If there is zero Corruption in my country, definitely there will be zero drugs too. Drugs can be sold because it made its way to my country through the back doors and law enforcers just turns a blind eye about it because they get bribed. Anyone who got caught will be released even if they are caught red handed because the judges as well are bribed.
I doubt that's true, there will probably be a lot less drugs yes but no society will ever be drug free. And it shouldnt be because drugs don't always mean trouble, most of the time they don't actually.