First, full disclosure: In my youth, I engaged in some serious substance abuse. Today I am a teetotaler, but I do not object to other people consuming alcohol. I hate smoke, but I defend the right of others to smoke. I disdain illegal drugs, but I don't feel that I have the right to impose that judgment on others. Also, while I am a free-market economist and believe that government has gotten way too big, I am not (for a variety of reasons) a card-carrying libertarian. That having been said, I find much of the libertarian argument in favor of legalizing recreational drugs to be persuasive, although I strongly dissent from one of the major implications of the libertarian position.
The basic libertarian premise is that each person (or at least, each mentally competent adult) has the innate right to choose what he consumes. The alternative, in our democratic political system, is the present reigning belief that the majority should decide what substances everyone is permitted to put into their bodies. I side with the individual over Big Brother on this point. This is NOT to say that I think illegal drugs are good or even harmless, NOR that the right to use drugs is unlimited. In my book, whatever momentary kicks one thinks he gets from drugs are illusory. I consider the risk-reward ratio of drug usage a losing proposition, since drugs cannot provide lasting benefits (e.g., peace, happiness, thrills, etc.) but can produce permanent damage or (with some drugs) lethal results in users. It seems to me, though, that the risks of drug usage are more properly the province of education—a responsibility for parents, teachers, ministers, etc.—than a matter of law enforcement. However, while drug use may be none of society's business in some circumstances, when a user is driving a car in an impaired state, or doing anything that endangers others, then it is society's business, and such behavior should be proscribed.
Libertarians also make a persuasive utilitarian case for drug legalization. It is indisputable that the market prices of illegal drugs are artificially inflated, not because it is inherently expensive to produce these drugs (on the contrary, they can be produced in abundance quite cheaply) but because of the gigantic markups added to the product to pay processors and distributors for incurring risks to life (from rival gangs, willing to kill to control valuable territories) and liberty (the constant need to evade law enforcement officers). The exorbitant prices of illegal drugs are problematical. The potential for making a fast buck lures people into the business who otherwise wouldn't give it a second thought. Also, the big money in illegal drugs has corrupted a significant minority of law enforcement personnel. To these costs of the war against drugs, we can add the huge financial burden imposed on taxpayers to pay for incarcerating hundreds of thousands of Americans whose only offense was wanting to get high.
Criminalizing drugs like marijuana and cocaine has hurt us internationally. For example, we pay South American governments to destroy their peasants' crops. This is repugnant. Mighty Uncle Sam can't stop drug demand at home, so he wages war on the livelihood of poor people abroad. At a time when China is locking up long-term contracts for valuable resources in Latin America, the United States should be working to establish friendly relations and mutually beneficial commercial ties with all those countries. Instead, we alienate a continent's people by turning their governments against them. This can only end badly. These countries will either be ruled by anti-American demagogues or by pro-American military regimes that lack legitimacy in the eyes of their own people—an inherently unstable situation.
The Castro regime, a human rights abomination at home and a perennial vexation to the United States, has been propped up in part by the financial transfusions it has received for allowing Cuba to be used as a conduit for drug smuggling by South American narcoterrorists. Those narcoterrorists have controlled huge swaths of territory, undermined democratic governments, and used violence against untold numbers of people. This leads to the problem I have with the libertarian drug-legalization argument.
Most, if not all, libertarians insist that drug usage is a victimless crime. It isn't. In today's world, its victims are legion. Whether they are innocent bystanders killed in gun battles between rival drug factions in American cities, or the thousands of South Americans who have been kidnapped, robbed, or murdered by the powerful drug cartels, any American who uses illegal drugs today has blood on his hands. I disagree when libertarians try to pin all the blame on Uncle Sam. Laws criminalizing drugs don't drive drug prices into the stratosphere by themselves. The other factor is American demand for those drugs.If you want to work for the decriminalization of drugs, then do so; but until those drugs are legal, don't tell me that you have a right to use them. If you choose to use illegal drugs, your choice is helping to kill people. This is not, and never will be, your right.