"we" need to talk to the disaffected youth before "they" are talked to by "them".
We need dialogue with "those" who say "not in my name" so that they can do some talking.
How we do it is not clear but a start must be made.

And I predict there will be a "temperance" movement/culture that is wary of large crowds, not the least because going there will be tightly controlled and patrolled. Otherwise it will all happen again. air travel is an example.

Cue internet & TV consumption of large events. So I will be paying for things I don't want, like football, just to see the one thing I do; eg on BT Sport! But given the above it is a cost I am willing to bear.

For evil to prevail, good men have to "do nothing".