If a different approach was taken in the war on drugs, for example securing the border, it is likely that the United States could have drastically reduced the amount of Heroin and Cocaine that was imported at a fraction of the cost of their current approach. This (of course) doesn't mean that people wouldn't abuse other drugs/substances though; after all, the average house contains several compounds that people can get high off of that would be difficult/impossible to control.
Now, if we lived in a society where an individual could fail without becomming a ward of the state, and having their poor decisions funded by me (and all taxpayers), I would support the elimination of drug controls.