Then arrest the parents for those crimes, instead of arresting them for possession of a substance. I don't care if a mother is cracked out, drunk, insane, or just an egocentric worthless person. If they are not treating their kids illnesses, feeding their child, etc. CPS should be taking them away.
I never understood the logic of "x leads to these behaviors (even though it doesn't always 100% lead to negative behaviors that I hear so much about) so we must make x illegal" when it's the behaviors it leads to that should be illegal.
For example, society has seemed to survive with alcohol being illegal even though it leads to drunk driving, domestic violence (and violence in general), addiction, and a host of other negatives. Yet we don't arrest someone for buying a bottle of Jack, we do arrest them for drunk driving, beating their wife, etc. Yet when it comes to other drugs, well, we like got to think of the children.
I would be willing to bet that if you studied the statistics there is a fairly strong correlation between abuse of substances like crack and meth and unstable and dangerous home lives for children. Often there is an "x" that leads to behavior. In fact it has been pretty soundly shown that behaviors do not just happen, they happen as a result of some stimulus and reinforcement. Of course, as you said, it probably doesn't 100% of the time, simply because statistically (and quantumly) speaking a probability of 1.0 for anything is virtually non-existent (hmm, is it a 1.0 probability that there is no such thing as a 1.0 probability?). Now if you can identify the stimulus and the reinforcements for a behavior, and you can change them, then you can change the behavior. Spanking a kid is an attempt at this. So is arresting people for possession of drugs. The problem comes in the analysis of the reinforcers. If they are not immediate (as in very closely connected to the behavior) and certain (extremely likely to occur), then they are weak behavior modification reinforcers. The best ones are usually positive in nature (as perceived by the individual), immediate, and certain. Certain and immediate to the point of being built-in. If you got shocked every single time you touched an exposed wire, how many wires are you going to touch? If you got a happy feeling every time you ate a donut, how many donuts are you likely to eat? Every behavior has both positive and negative reinforcers (or nearly every) for any given individual. Using drugs is apparently an immediate positive - you get high - and the negative (go to jail, lose your job, etc.) are neither immediate, nor certain, and sometimes not even viewed as a negative by the user. This separates poison from drugs. The result of ingesting poison is immediate (usually) negative and certain. Of course, using "poisoning" to commit suicide shows that for some people the outcome is a positive rather than a negative.
I think the decision to make substances like that illegal, initially, was politically motivated. Really, imo, it should be motivated on a cost-benefit analysis (now we are getting into the realm of philosophical ethics). What is the cost to society of allowing all substances to be legal? What is the benefit? Which is greater? Remember, benefits can be avoidance of costs. So is avoiding the cost of the war on drugs better than the cost of the drug use itself?
Is the societal cost of wide-spread marijuana use exactly equal to the cost of meth use? I would wager the answer is no. Some substances are going to have such a strong influence on behaviors, or are so addicting, that the costs begin to get very high, very fast. And the benefits are surely negligible in any case - is there really a societal benefit to drug use other than cost avoidance?
So knowing that there is a high probability of drug use leading to destructive behaviors, and that there is no true benefit to society other than potential cost avoidance, it becomes an equation of whether everything should be illegal, or just the "worst" ones. So far our society has opted for the "worst" option, but then you get the discussion of where to draw that line. It is fairly arbitrary, and again political. This is seen in the fact that alcohol abuse results in more deaths every year than all other drug use combined, yet alcohol remains legal. Again, here is a case where society has determined that the costs of alcohol use (drunk driving deaths? broken marriages perhaps? etc.) are outweighed by the benefits like jobs (bars and alcohol companies) getting drunk and its perceived "fun-factor", etc. So in this case we do punish for the ancillary crime, but not the use of alcohol itself.
Even still it could be argued that meth use as widespread as alcohol use would be far more detrimental to society. Some drugs like meth, crack, heroin have a far greater impact on the individual. It is possible, in fact very common, to be an occasional drinker and not be an alcoholic. It is far less likely to be able to be a "casual" user of meth, or heroin. These have been shown to develop physical dependence in as few as 2 or 3 uses. Also, the possibility of overdose on alcohol to the point of death is relatively remote. For meth and heroin it is a constant possibility as it takes far less of those drugs to kill you than it does alcohol.
So an argument could be made to make certain substances illegal, completely independently of its perceived effect on children (in this case, that is just another cost to factor into the equation).
(the irony of this ramble is that I am a little high on percocet and muscle relaxants because I fell and hurt my back recently, so things come out in a mostly disconnected stream)
