I wonder what a world would be like, where all drugs are legal or decriminalized (it'll happen) and all these government agencies begin to focus on fighting real crime. Maybe the DEA will begin taking a shit on the FDA and pharmaceutical company, and the police will begin going after real criminals who commit crimes that actually involve a victim that's not the perpetrator himself (how ridiculous.)
You don't have to wonder -- Portugal is something similar to what you're wondering about. The UN and US bitched and moaned in 2001 when Portugal decided to decrim all drugs, including coke and heroin. The sky didn't fall, crime didn't sky rocket, and the "moral fabric" of society stayed in tact. In fact, rates of usage for young people are lower in Portugal than most of Europe and lower than the US. It can work, it has worked, and it will work.
The trick is getting the US to basically admit, we were wrong, we've been wrong, and we encouraged countries the world over to be as wrong as us... and we're going to change all that. It's tragic because that's no excuse NOT to do it but that is the major hurdle, on the surface. As many of us know, big business interests are involved as well but that's a murkier water altogether.