I don't know where you got that textbook definition, but it sounds useless to me. What violence and intimidation is not done in the pursuit of political aims, aside from low-level street crime? Even adding the qualifier against civilians doesn't seem to help much, as civilians not being deliberately targeted is very much the exception in warfare historically.
My definition is "Violence and intimidation, conducted by an organization not directly under the control of a national government, targeted deliberately at civilians, for a political purpose". Much of what is popularly referred to as terrorism is closer to guerrilla warfare.
I don't entirely agree with the linked post above, but I would also not call ISIS a terrorist organization. They may be major-league assholes who need to be dealt with somehow, but they're more of a statelet attempting to practice regular warfare, including controlling a specific territory, establishing their own political system, etc.
My definition is "Violence and intimidation, conducted by an organization not directly under the control of a national government, targeted deliberately at civilians, for a political purpose". Much of what is popularly referred to as terrorism is closer to guerrilla warfare.
I don't entirely agree with the linked post above, but I would also not call ISIS a terrorist organization. They may be major-league assholes who need to be dealt with somehow, but they're more of a statelet attempting to practice regular warfare, including controlling a specific territory, establishing their own political system, etc.