> Now you could argue, as you suggest, that we are all accountable for our actions. Which presumably is the argument for legalizing heroine / cocaine / meth.

That's not the only argument. The war on drugs is an expensive failure. We could instead provide clean, regulated drugs that are safer than whatever unknown chemical salad is coming from black market dealers. This would put a massive dent in the gang and cartel business, which would improve safety beyond the drugs themselves. Then use the billions of dollars to help people.