Great discussion. Appreciate Allforcnm for starting and really useful adds from the other posters. To me "Not enabling" does not mean treating our challenged loved ones harshly or disrespectfully. Of course they need to be treated differently because of their addiction. Addiction is a mal-adaptation to life. Positive reinforcement for positive actions and allowing natural consequences for negative actions seem to make logical sense. Each situation is different. Addiction may be mild, moderate or severe. The age and maturity of the addicts matters as well.
In my case my son is 21. He has not achieved the maturity of a normal adult because of his drug use which started in his early teens. I try my best not to enable and asked him to leave our house because of his use, but still maintain some communication with him and let him know regularly that "when he stops digging", I am still here to help him.
It is of course possible that he continues digging and our communication will then become difficult and eventually cease. Hope for better things but be prepared for worse things.