Regardless of how you may feel about it, that’s how the governments of most other Western countries saw it. This is evidenced by US bases all over the world, low investment in national defense by most NATO countries, the dollar being the world’s primary reserve currency, etc.

The diminishment of global influence and power is not because of those things, but because of domestic affairs: in the richest country in history, businesses broke the social contract with workers, the cost of health care skyrocketed as hospitals became for-profit business, and half the country was too brainwashed by consolidated media conglomerates to see what was really happening.

Basically, the libertarian values that have always been the underpinnings of American society finally reached their apotheosis at the same time the Internet and propagandist entertainment news caused the cultural fabric of society that had formerly acted as a counterweight to begin to unravel. Every man for themselves writ large. The chickens came home to roost.