Please allow me to add a few further thoughts.

Do you think there are only good and bad people?
Do the 'good ones' walk with peaceful demeanour?
Dispensing good humour as they go?
Whilst the 'bad ones' walk with cunning expression?
Twirling a luxurious mustachio suggestively?
Ready to tie poor Nell to the railroad track?
I don't think that is anywhere near the truth.

I think it is reasonably well established that everything about a person's genetic makeup is there right from the start.
Basic character and personality are embedded in a person's DNA?
The person can learn skills to add to these things.
So he learns to control the way he behaves to some degree.
But we have no practical means of making significant changes to our basic genetic makeup.
So a person will remain who he is and what he is.

Every living thing on earth is programmed to behave in a particular way.
We are all born with a mental outlook which is different.
However different that is, that way is 'normal' for us.
Many are born without conscience, which is normal for most of the animal kingdom.
Those without conscience can act in a way we consider to be harmful.
And will do this without pause or regret.

So, some of those 'strange' persons you see causing unrest overseas are being 'normal' by their natural standards.
They believe just as fervently in the justness of their cause and their actions as you do of yours.
They do not see themselves as behaving badly, and neither should we.
And note there is not a twirled moustache in sight.
Though there might be a beard or two.

Read the last paragraph again, and consider it carefully.