Drug usage is not only physical addiction for certain drugs but the biggest problem the government would face is the 1st stage of overcoming the mental addiction. If it was never illegal chances are barely anyone would do it. However since the issue is already there, most people would fall into that mental addiction hold for at least 5-10 years before anyone could get out of the slump. Thousands would die from heroine/cocaine/meth overdoses. As far as alcohol goes, the prominent and rich/government are into it so it gets taken into a lighter category. All of the prominent people tend to support alcohol, where your regular junky smokes pot and gets arrested for it. It's a screwed up system. If you can't die from it, legalize it. That's what I say, and alcohol is even worse than pot because you can die from alcohol.Alcohol is a drug too.
When legalised, most dealers will fall apart and might give jobs to people.. but how do you control people's dosis? Only with education and more deep prevention schemes other than just limit the amount of drugs one could buy..
Have you seen joe rogan and johann hari talk about it. trust me you'll enjoy it. it first interested me.Depression is also a big issue everywhere and if you can go somewhere to buy hard stuff like cocaine/heroine you can easily just commit suicide without further ado..
This is far more complex honestly.. legalizing would help to destroy kingpin's empires but what do you do with the junkies?