The US shouldn't be thought of as a homogenous place. There are parts of the US -- most of it, geographically, as far as I can tell -- which are basically indistinguishable from their Japanese counterparts in crime rates and levels of social trust. Almost every good thing you can say about a Japanese town is true of a (smaller) American town, and vice versa. I've lived in nice places in America where crime was shocking and essentially not heard of; I've also lived in places where some lunatic with a screwdriver threatened to stab random passers-by six times before breakfast, and the police just sighed and took Philip McStabbins to jail overnight for the 262nd time because the DA wouldn't prosecute.
And that's the thing, isn't it? America is mostly super-low crime, but for some reason we have a dysfunctional criminal underclass that just won't go away. Japan seems weird to us because theirs is smaller than ours (and often held in check by Yakuza higher-ups with calmer heads.) Why do US cities have so many neighborhoods where you Do Not Go, while almost all of the US has no neighborhoods where you feel even vaguely unsafe?