What's your problem with it in detail? I mean it's a Peace index. The USA isn't exactly a peaceful country and few would even value that if it were. The points where the US scores badly are often aspects many Americans actually like, such as the high militarization of society (5/5) or the high rate of incarceration (5/5). The same goes for points such as easy acces to weapons (3/5) or the several aspects that are related simply to being in a war. It seems a bit contradictory to have a wish to be high on a peace index given the nature of American society ?