'Terrorism' is simply the State's euphemism for poor man's war. And all people are capable of it, if forced into a situation that compels them to react that way. I say 'react', because it is usually a reaction to State terrorism of some kind. The word 'terroriste' comes from the French Revolution, when cells of assassins were out hunting Royalist leaders. As a euphemism for poor man's war, we can credit that to Nazi Germany, which ordered that all mention of European resistance fighters describe them as "terrorists".Bureaucrats that failed to do that were summarily arrested, and imprisoned, or worse.
This is the origin of the saying that" One man's terrorist is another man's freedom fighter".

I wonder what color the crusaders were?

White men have committed more mass shooting than any other group.

[newsweek.com]