Terrorism, ladies and gentlemen, in my eyes I have a very, very, very simple explanation. Gangs of criminals, killers, used unfortunately by certain governments in the past for political purposes, who are on their own now as gangs.
Moral justification is a powerful disengagement mechanism. Destructive conduct is made personally and socially acceptable by portraying it in the service of moral ends. This is why most appeals against violent means usually fall on deaf ears.