The temperance movement was mainly related to alcohol. There were groups who wanted abstinence from everything but that was not its primary focus. They may have played a part in said act but I don't know. They were definitely not the driving force behind it though. Racism played a bigger role than the temperance movement. The government was also aware there was a very real problem with drug addiction.
I'm curious about this sentence -- to what are you referring, and where specifically in Europe?
The government‘s not passing out drugs in the street, like US media likes to suggest.
It isn't the same drug as fentanyl, but it never really stopped being the plan that we will take people from 'the list' and just keep metering opiates out indefinitely. GGP posted this in a way that seemed to allude this was not currently the case.