Deborah K,
Although the source to which you referred (“Substance Abuse: The Nation’s Number One Health Problem”, Brandeis University
http://www.rwjf.org/files/publications/other/SubstanceAbuseChartbook.pdf ) is not accessible, I am going to assume you have misrepresented the stats. You said “aside from the crime and violence…untreated addiction costs America $400 billion per year”, yet all reviews of the study I’ve seen indicate no such distinction. IOW the figure likely INCLUDES crime and violence and your point is mostly circular - and prohibition is to blame for incurring a large percentage of that cost. If you disagree, please provide a workable link to your source AND quote where it makes said distinction. Until you do that, I will also assume that your other sources also made no such distinction.
Now … even if you are able to do that, you STILL have no argument against the complete legalization of all drugs. Since you base your position on “costs to society”, it’s clearly fallacious. All kinds of things incur “costs to society”, but most are not even considered as candidates for prohibiting. Sports come to mind. What is the cost of legalized sports? I don’t know the figure but I do know that it would never justify prohibition even if prohibition were to cost less. The main reason should be excruciatingly obvious to any libertarian; that since that the behavior risks direct harm to no one but the participant, it violates no one’s rights and should not be controlled. As MRoCkEd said, “in a free country, adults should have the right to harm themselves”.
But nevertheless, you seem to disagree with this definition of individual liberty. You said: “addiction … hurts not only the addict, but the people who employ the addict, and the people who love the addict.” You thereby attempt to take an individual behavior that directly harms no other and transform it into a non-consensual rights violation (an act of aggression). I’m sorry, but since there are millions of completely legal things that also present an indirect risk to employers and loved ones, your attempt fails. Unless you are arguing that virtually no thing or behavior in this world should be completely legalized (since virtually EVERYTHING falls into your possibility-category of indirectly affecting employers and loved ones), your reasoning is not consistent (or valid).
You wrote:
“I also know that whether or not hard drugs become legal, addicts will always commit crimes to get their drug of choice, if they don't have the money to buy it. That is NOT going to change just because their drug becomes legal.”
I’m sorry if I’m being too direct with you. I thought I was dealing with someone who had given it some thought, but your quote suggests a lack of education on one of the most fundamental elements of prohibition: black-markets economics
You wrote:
“How do you propose to deal with it? Assuming I'm right, and addiction would increase exponentially.”
You deal with the actual non-consensual rights violations – not the consensual things you think might influence another to commit them. You are not required to deal with anything more; but if you do, YOU become the violator and the one who needs dealing with. That’s because prohibition violates rights, and drug addiction does not. Legalization does not claim to solve the problems related to drugs; only the problems created by prohibition; because prohibition not only fails to solve them, it makes them far far worse.