Fear is politically fungible, able to migrate stealthily from one cause to others, and from one host to others. Fear can also pool or coalesce around shocking experiences. These gymnastic capacities are what give terrorism its social and, ultimately, its political punch.
The forms of social authority capable of motivating individuals to engage in acts of violence and terror are not constant across all societies. Differing social structures, as well as different cultures associated with them, affect which modes of persuasion and manipulation work best to generate the worst sorts of behavior.