You will never solve the "problem" completely, until you can change the fact that people like to get "high". And that's not going to happen anytime soon, if ever.
Ancient people developed brewing and fermenting, and found plants that could be eaten or smoked to make them feel good. That hasn't changed, and isn't going to.
I see two separate, but intertwined problems. First, that (some) drugs are illegal, and second, how we go about enforcing those laws.
We are constantly hearing about the "costs to society", and while there is a validity to the concept, I think we have gone well overboard with our concern about it. We too often look at results from a group, without considering that the group is made up of individuals.
The focus on possession and use of drugs as criminal, is, I feel, the wrong way to deal with the problem. What people do under the influence is what causes the problem, not the possession of a plant or compound.
A drunk driver nearly killed my family. It wasn't the beer that made that happen, it was the drinker. And what he choose to do after drinking.
In some ways, its a lot like gun control. The problem isn't the guns, its what some people do with them.
And what is the answer our govt and (some) segments of our society give us? A top down war on things, more than on harmful actions.
Of course, if you don't have a thing, you cannot do bad with it. So we all get forced to live so that stupid people are slightly less likely to be stupid?
As a people, we are kind, caring and considerate (of course individuals can be petty and spiteful). We dislike seeing anyone hurt or suffering, even through their own actions. This is a noble sentiment, but there are limits to which this is practical, or effective. AND those limits must be balanced against our personal liberties and freedoms.
We make compromises to our freedoms all day, everyday. That's how society functions. We have set rules, and generally follow them. About virtually everything. However, where one sets the rules, and how they are enforced is critical to our liberty.
Our history is full of things that are now crimes, that once were not.
We've tried a lot of things, and often the "solution" only made the problem worse, or actually created more problems than it solved. To my eyes, the war on drugs has created more, and worse problems than it has solved.
In war, when you consistently fail to achieve your objectives, its time to seriously consider changing tactics. I think that's quite apt to the war on drugs as well.
All else being equal (and it almost never is) bigger bullets tend to work better.