Why does America believe it's entitled to Nuclear Weapons & that certain other countries aren't?

I’ve been thinking about who are the craziest, most extreme people on the planet. The people you really don’t want to be armed to the teeth, the most unhinged, the most out-there, with the largest number of whack jobs, the least responsible, & most violent…. &, well, it would seem that our American cousins top the list of pretty much all of these. This is just anecdotal, an opinion. So why is ok for this right-wing, crazy nation to have nukes, but not others?