One of the things that sometimes gets lost in all the talk about drug laws, harm reduction, classification etc. is the sheer amount of time that the police spend on activity relating to the existing drug laws.
They spend millions of man hours every year, a good chunk of it on arresting and processing people for possession of drugs that were only going to be used by that person. In other words they were not going to harm anyone else. It also includes time spent chasing small time dealers who are supplying drugs like cannabis and ecstasy (the ones that Professor David Nutt says are less harmful than alcohol) to friends and acquaintances.
If drugs were legalised none of this time would need to be spent. That would mean that those millions of hours would be freed up for police to investigate other crimes like burglary, muggings, assaults etc. The sort of crimes that the vast majority want to remain crimes. Unlike for example cannabis possession which 70% of people in a recent survey said they wanted to see legalised in some form.
We have to recognise that if we have these laws, then the police will spend time enforcing them. As any economics student would tell you there is therefore an opportunity cost whereby they cannot spend that time investigating other crimes.
I strongly suspect that if drugs were legalised in this country then crimes such as burglary and mugging would drop dramatically anyway as there would be much less need for problem drug users to fund their habit in this way. However it would likely be a win-win because of the remaining burglary and mugging (and all other crime) the police would have more time and resource to devote to investigating and solving them.
And if 70% of people think that cannabis should be legalised then in what way is the police spending the public's money arresting cannabis users serving all of our interests?
I for one would much rather they spent their time investigating crimes that affect other people such as burglary and muggings and that pretty much 100% of people think should remain illegal.