It really is a difficult problem. Sweden legalized heroin in the 60s and it was a disaster. On the other hand, enforcement only has a moderate impact, but comes at a huge financial and social cost. And while I don't support it, the only country with a measure of success seems to be Singapore, where you just hang anyone who has more than single dose in their possession. Maybe the grim reality is hanging a few hundred…
Success being what? People not doing drugs? Who said that's what people want?