While it may sound trite, decency really is a general characteristic of Americans, generally going back to 17th Century Anglo-Saxon Protestant ideals of 'Christian brotherhood' and 'fair play', which have lost their orignial ethno-religious context and been dissolved into common American culture. While this makes Americans more decent towards each other and 'good' strangers, it also makes them exceptionally cruel and merciless towards those they consider enemies/traitors, as is apparent from America's historical record of segregation and conquest.
