More of a principle thing.
UK, USA, either would be good.
Well, they're both drugs. Sure different ends of the scale, but still...
Tobacco is highly addictive, one of the most addictive drugs bar cocaine and heroin, and alcohol is pretty addictive too. Both much more addictive than marijuana. It's actually the level of addiction that is what makes drugs dangerous as you keep going back for more and suffer from the long term side effects.
So yeah whichever way you look at it marijuana is safer than alcohol and tobacco.