As noted in a recent article entitled For Reasons of Their Own, it is remarkable (and a counter-intuitive sign of the times) that the Tucson gunman who killed 6 people and wounded 14 others is being painted by the media as mentally disturbed .... with no mention of his act being that of a terrorist. Like Timothy McVeigh, who was immediately labeled as a terrorist after his participation in the Oklahoma City bombing, Jared Loughner "targeted a symbol of government power [Congresswoman Gabrielle Giffords], and hurt innocent people. Like McVeigh, Loughner had a complicated relationship with the military and, like McVeigh, he apparently had a deep mistrust of the American government .... But we call McVeigh a terrorist. Why isn't Loughner a terrorist? Has American redefined its criteria for who can be one?
" .... 'two common elements are usually found in contemporary definitions: (1) that terrorism involves aggression against non-combatants and (2) that the terrorist action itself is not expected by its perpetrator to accomplish a political goal but instead to influence a target audience and change that audience's behavior in a way that will serve the interests of the terrorist'.
" .... Are the insane unable to plan? Do only terrorists plan? Is he a terrorist, or is he mad? The word terrorist remains unspoken. Apparently it could never apply here, not now. The media's concern with sanity or insanity, and its quickness to find for the latter, indicates a reluctance to view terrorism as psychological, and to flip things around, a reluctance to view a troubled white American with no religious ties as a terrorist. In 1995, this was not a distinction we made so easily."
It is a fascinating and disturbing distinction, and subject to relativism. From the point of view of Muslim fundamentalists, Americans are terrorists and infidels. Similarly, from the point of view of American civilians, many Muslim extremists are terrorists -- but then, so are many Americans. Consider the Ku Klux Klan, or covert actions by the CIA, or the abundance of radical survivalist groups in our country.
Terrorism is more common than we imagine. Loughner was clearly motivated in part by his exposure to right wing Tea Party propaganda, which he mimicked online. He was also clearly capable of carrying out a systematic plan to stalk his intended target over a period of months, and to secure the weaponry and ammunition needed to try to assassinate her and everyone around her, at a particular time and place.
In my opinion, the terms terrorist and sociopath are not mutually exclusive. There are degrees of insanity, but not many gradations of terrorism. Committing a terrorist act makes you a terrorist, whether you are superficially rational or barking mad.