At the start of this thread is a comparison between deaths attributed to legal drugs such as tobacco and alcohol and illegal drugs.
If all illegal "hard" drugs were made legal and "controlled" in the same way alcohol and tobacco are controlled this means that they would be freely available to everyone. There would be no "stigma" or risk of breaking the law attributed to drug use. The marketing for such drugs would be very slickly managed by the corporations manufacturing them. The number of people using hard drugs on a regular basis (in the same way they use alcohol) would increase many times over. So would the deaths attributed to such use.
I am somewhat in favour of legalizing drugs not because they're safer than alcohol (I bet they're not) but because I think taxes should be collected from them and monies used in rehab and medical care for those who become hopelessly addicted to them. I also object to the idea of the drug lords killing and getting rich tax-free from the inflated prices that illegal drugs currently sell for.
If we take SIN's "alter-argument" which seems to be that "alcohol/tobacco are worst than illegal drugs so why are they not illegal?": Again, same problem, make alcohol/tobacco illegal, drive it underground, less control, no taxes...oh, and very bad people getting rich off of it (in the same way that drug dealers amass incredible wealth from peddling their wares).
There is no easy solution.