Shibley Telhami offers up a definition of terrorism vs mass killings in Lawfare that I found interesting but muddled:
Regardless of the legal distinctions, I suggest that there is a prevalent sense that terrorism occupies a higher order of immorality, and offer reflections on its origin and justifiability.The definition of terrorism includes both ends and means, but moral judgment is principally based on the means. People can morally sympathize with the motives behind some ends of terrorism—freedom, self-determination, etc.—while rejecting the means. With “hate crimes,” on the other hand, both ends and means are objected to, by definition. “Mass murder” is at least as morally objectionable as terrorism, and sometimes more. Yet “terrorism” adds an irrational stigma that elevates moral objections.
There is a similar stigma associated with “suicide terrorism.” All terrorism is morally objectionable based on its targeting of civilians/noncombatants. The “suicide” part adds little value to the moral objections. Without the objectionable targeting of noncombatants, sacrificing the self for a higher cause is celebrated by almost every society. Yet for some, this form of terrorism seems to occupy an even higher level of immorality.
I would look at acts as having two parts – the goal, and the activity that is implemented to move the state of the world closer to that goal, which is to say, many actions are merely part of a larger campaign; although none by themselves is adequate to the goal, as a cumulative effect they will accomplish the goal, at least in the minds of the planners.
So we can classify goals into at least two categories. First, there are those which are putatively political in nature, whether it’s the assertion that a different party should be in power, the revolt of the oppressed in order to relieve themselves of an oppressive regime, etc. At their heart, they are about who will control the community, even unto definition of community, and they can be thus classified as apparently social. I say apparently because these sorts of actions may mask the personal ambitions of one or more people, who intend to use them to implement those ambitions with little regard to the impact on the community. These are moral judgments.
The second category of goals is the explicitly selfish, where society’s state is not considered or is deliberately and negatively impacted. This can contain such diverse goals as buying a refreshment to deliberate Acts of War up to and including insanity.
The activity implementing the goal will also have a moral dimension; whether it is unmodified by the goal is up for debate.
To my mind, terrorism is that collection of goals and activities implementing goals wherein the goal is of the first category, i.e., an attempt to influence a society for a political goal, while the activity is of a negative moral dimension – in this case, mass killings of civilians.
Thus the Twin Towers and the various incidents in Europe over the last few years are terrorism, as well as the Oklahoma City bombing (an anti-government goal) and the tragedy at the AIM church in Charleston. The Unabomber was a serial but not mass-killer, but we could argue that is terrorism as well, if we expand the definition of the necessary activity slightly.
On the other hand, without any information as to the Las Vegas shooter’s motivations, we must conclude it was some internal, selfish motive, and simply call it a massacre; ditto the Valentine’s Day massacre, Ted Bundy, etc.
Getting back to Shibley, he says ‘Yet “terrorism” adds an irrational stigma that elevates moral objections.’ I’m not quite sure how to take this, but I think irrational may be a strong word, if only within my informal attempt at systematization. Terrorism, in my definition, implies a certain coordinated, shared idea among a group with greater resources than a single person. Is it irrational to fear them more than mere greed-borne violence, or that originating in essential malice? I would have to question that thought.
But, in the end, Shibley’s concerns are somewhat beside the point in the eye of the political hurricane, especially that of Trump. Politicians often have little but words, and they seem prone to use them to advantage, rather than to convey truth. For his community on Lawfare, I am sure they are valuable; but will those who truly need to understand them even hear of them?
