It depends what you mean by effective and ineffective. Nuking San Fransisco would prevent tons of drug use, but is not an effective way of solving society's ills.

> This only matters in some utilitarian conception where all net suffering or utility or whatever is created equal.

Drug laws not only hurt drug users, but further criminalize nonviolent users who commit more crimes, fund organized crime (here and especially in other countries), cost billions of dollars to society in court systems, prisons, police officers, and lost productivity.

If your solution to that is literally kill people without a trial for drug use then some of those clearly wouldn't apply, but that's honestly a pretty sick worldview. I'm not sure if you're younger or maybe lived a more sheltered life and weren't exposed to drug users or similar groups of people, but you might change your tune if you knew someone affected by it (whether they were a user or the parent/child/spouse/friend).

I wonder what you think of other countries which have much lower rates of drug abuse yet don't impose punishments as harsh as the US?