Waging a war on drugs has an interesting side effect that it also reduces harm. The "War on Drugs" does not necessarily target the low level street uses. Even though at its peak it got overly exuberant in the days of "zero tolerance" the main enemy is the major suppliers. Let's continue to focus the war on the major criminals and we can still provide care for the victims.
The war on drugs was first declared in the 1980s. In that time, there has clearly been no victory. The problem is that young people have a lack of opportunity and a life from which they need to escape. So the best way to eliminate drugs is to provide opportunities for young people, improve mental health services, and respect those who are different than ourselves.