There is no perfect system to control access to drugs; but, there are systems that are clearly and demonstrably worse, with highly destructive impacts on society. There are no benefits associated with the war on drugs, only costs (see Arthur Benavie's new book Drugs: America's Holy War for an economic and social analysis of the impacts ISBN 978-0-7890-3841-8). By any measure prohibition is an ineffective, counterproductive and highly destructive policy.

There will always be a small segment of the population who circumvent any regulatory system. This happens to some degree with alcohol and tobacco products. However, because these substances are legally accessible, very few users are willing to take risks associated with using illegal purchased products (trafficking, adulteration, criminal networks, etc.). This may change for tobacco if prices continue to escalate sharply and create conditions that open space for a black market in lower priced tobacco.

Despite marginal leakages in any regulatory system, there is far more control and far fewer adverse impacts associated with mechanisms that allow regulated legal access than under prohibition. There is little evidence to support any assertion that illegal substances would or could be more readily available than they are currently under prohibition. Illegal drugs are readily and easily accessible to people of any age under prohibition. Under prohibition a grade school kid could be given money and sent to the corner by his parent to score drugs for them from a dealer and would probably return with the drugs. It is hard to argue that a regulated system of legalized access would provide easier access to psychoactive drugs.

There will always be some diversion of substances and illegal sales of fraudulent drugs. But given the available evidence (and there is a lot of evidence available) it is unlikely that (a) illegal sales of drugs diverted from the regulated system, (b) illegally produced substances or (c) fraudulent substances will be as serious or destructive as the incredible array of problems produced by the war on drugs.