I don't doubt that the Norwegian system has other aspects / safety nets that help here, but the article says they had a 70% rate as recently as the 1990s. It would be silly not to look at that 70% -> 20% drop and at least try and learn some of the lessons from it.

"Officers are trained for 2 to 3 years before being sent to work" seems like a good one to start with, as does the skills building to prepare them for the outside.