There's a huge difference between a terrorist and a guerilla. A guerilla only target military assets and personnel. This isn't terrorism, because the military is used to attack and defend. A terrorist *specifically* targets the civillian population, who are not meant to defend themselves against a foreign or domestic threat, in hopes of inspiring panic and unrest. If on 9/11, Al Qaeda had only attacked the Pentagon, and not used a plane full of civillians, they would not be deemed terrorists, because they would have only attacked military targets.
