I think, people must be vaccinated against radicalism, again and again, by experiencing the outcomes for themselves.
If you are discriminated and robbed in your favorite online game, for no other reason then who you are or your name- without any success when appealing to the "state", you begin to understand what it is like to have been a jew in europe.
Another difficult fact remains- only the prosperity of the past and the nuclear weapons kept these dark tides at bay.
The politics, the memorials and the activism did & do nothing.