You have to work with the world as it is, not as you'd wish it to work (especially that it likely couldn't possibly work that way anyway). "State of nature" sucks, because nature sucks. All the nice and good things come from building systems, social or otherwise, on top of the natural state of things - systems that work with our natural inclinations, instead of pretending they don't exist.
Right but nature doesn't suck. You make humans sound incapable of cooperation when this evidently isn't true. In this world uncooperative behavior is mostly a choice. Particularly in the west.
> To the extent humans fail at cooperation, that's nature at work. When we cooperate, we defy nature.
Well that seems a little silly, no? Humans are social creatures; cooperation is just as natural as any other human behavior (including fallibility). It seems almost a little christian in its doomful profession that humans are only our worst attributes.