"Good guy" -- the description of Staff Sgt. Robert Bales by neighbors that is headlining in the American media -- is pretty much the way ordinary Germans saw other Germans who brutalized people in extermination camps in WW2 (See Daniel Goldhagen's Hitler's Executioners: Ordinary Germans and the Holocaust). "Good guy" is how most family, friends and neighbors in the USA described John Demjanjuk, the Ukranian-born Nazi extermination camp guard who was deported to Germany for war crimes and who died Saturday, convicted of his crimes but living free in a German nursing home. And "good guy" is how family, friends and neighbors described Ander Behring Breivik, judged by his countrymen to be "mentally unfit" when he massacred dozens of young people in Norway because his government tolerated Muslim immigrants.
Imagine an Afghan who came to the USA and murdered 16 people, mostly women and children, and burned their bodies. Then the Afghan government whisked the guy away and said, "Trust us, we'll take care of the matter," and the Afghan press was full of reports saying that neighbors in Afghanistan liked the guy. An American president who allowed this to happen would likely be impeached. And would Americans really care if some foreign terrorist who had just shot or blown up a bunch of kids sitting at a family diner had done it because he had snapped, or was drinking, or was under stress, or for any of a dozen possible motives our press has proffered for Bales' actions?
I'm not against factoring in such motivations in passing final judgment, but only if consistently applied. The problem is that Americans, just like most other nations and cultural groups, believe that most of what they do is motivated by a morality based on Golden Rule principles of fairness and do no harm (unless first done to you), and that heinous acts committed by one's own kind occur because the actor has a screw loose or was suffering unbearable social or economic pressure. In fact, recent work in evolutionary psychology indicates the Golden Rule principles operate fairly in all cultures, most of the time, but not between cultures. People in other cultures are generally thought to commit terrible acts for calculated reasons, underscored by some perverse morality that can be readily discounted, so that only the consequences of their actions should be judged, whereas for one's own group motivation is, and what ought to, mostly count.
What goes for individuals, goes for whole nations: When our country kills and shreds the flesh of others, whether flatly described in technospeak as "collateral damage" involving a few dead individual bystanders or "strategic bombing" that annihilates tens of thousands of civilians, it's almost always for fine moral reasons and because we want to save lives in the end; but if others do similar things with similar consequences, it's almost always because they are calculating evildoers. This asymmetric mindset has been with us since our species emerged from the caves, and is a continuing cause of much misunderstanding and distrust between groups in the organized anarchy of our ever-violent world. In this regard, America is unexceptional in its reaction to a massacre perpetuated by any of its own against others.
Now, factor this mindset into to the mundane workings of the extraordinary technocratic bureaucracy behind today's war-making industries, which has more destructive potential than all of the world's previous wars combined. Its managers are often the "best and the brightest," with a lot of nice guys whose team spirit differs little from that found in an advertising firm, cabin crew or Internet company. The flat language of technology and bureaucracy, and the ordinary career trappings of promotions and perks and Christmas parties, only mask (and so make possible the psychologically impossible brutality) of this awesome killing machine.
Steve Pinker, in The Better Angels of Our Nature, documents how everyday violence between people has declined markedly since the Stone Age. But this underplays another well-documented trend (known as a "power law distribution") that big wars (as well as large terrorist attacks) over the last couple of centuries, though increasingly infrequent, are very many times more murderous and catastrophic than those preceding. Each bigger event generates more world-shaking consequences than the last: politically, economically and socially. Lacking the will and means to consistently impose a universal moral code across all peoples (and the human evolution and history of intergroup rivalry says "Don't hold your breath" on this score), perhaps the only way to ultimately outwit the bad beast of our nature from doing all in all of us in the Space Age is to ignore how nice or not are the guys who prepare the killing, or how good or not may be the guys who do it, and focus mainly on treating the consequences of killing.