The goal is to get it where no Americans are distributing or consuming illegal drugs, so the win condition will involve understanding the flow of drugs within the country, including across state borders (by cars with license plates on them).
If you are willing to spend $80K per year on each drug user to keep them in jail, why are you unwilling to spend a fraction that amount of money on helping them kick their addiction?
Think of it as an investment. If we can save a bloodline from being corrupted by drugs it can have a big upside if you include all of the productive goods and service the dependents may generate. It can also result in improved safety in public which has exponential effects in being able to use that area in the real world.
>why are you unwilling to spend a fraction that amount of money on helping them kick their addiction?
Considering there is no drugs in prison they will be forced to kick their addiction.