The behavioral degradation of the US is very easy to see from the outside. It's when you reduce all human existence to economy. But turns out money chasing is a bad substitute for morals, principles and social connection (the true version and not the shallow caricature that is sold online these days).
How could this possibly be seen from the outside the US? All I can see from the UK is a significant increase in the amount of whining coming out of the US, but that's just social media.