Well the best in class of developed countries. The US does have the largest military, political hegemony, economic hegemony, and a huge amount of cultural influence compared to other sovereigns.

With that in mind the standard I have is high (top in class of developed countries for certain statistical measures) when you think about these social, cultural and economic dominances reverberate throughout the entire world.

You haven't explained why you think the decay is somehow worse in America. Only that if it was worse it would be influential.