So lets get this straight. The whole world of heroin addicts will flood to Norway, but then the people nearest to Norway (who likely don't have to fly) are going to be impacted by this illegal trade?

Selling something that is free is not a lucrative business for the Mafia. I think you have to make up your mind about the exaggerated scenarios you're imagining.

Here's two straightforward policies that would ameliorate these concerns:

1) Dole out the drugs on site. This is done already all over the world all the time. No take home doses.

2) This is a last resort of Norwegian citizens who have tried other methods of recovery. If you read the article, you'd see it will affect about 400 people. This is a good start, hardly a global heroin empire.