Nick, let me assure you not all Americans are xenophobic, obnoxious and self opinionated. But there's no doubt they do have their fair share. I think what we have here is a server case of Narcissism..let me elaborate.
A narcissistic personality has an exaggerated sense of self importance, Their grandiose claims are usually, but not exclusively, a superficial yet plausible fabrication of their own life ( i hope i didn't lose you there )
They crave expressions of envy all the time, the sincerity of the expressions is not an issue for them, all that matters is frequency and volume.
Narcissist's have a arrogant, haughty, patronising or contemptuous manner to others, while being flirtatious and kind to those who are unaware of their disorder................get it.