Earlier quoted context omitted.
Exactly. I had this exact thought experiment of "What if America were no longer Hegemon". So, I looked at other historic examples. The British, Dutch, and Spanish. (You can add German/Austrian and the French, close contenders). They're all still very well-off!
If Britain were a US state it would be between Mississippi and Alabama in GDP per capita. Not sure I’d call the place well off. Granted, a lot of the reason they’re in this situation is because they put everything into stopping the Nazis and thus saving the world. The US kinda lucked into inheriting the UK’s wealth.
Japan is even lower on the list, but personally I’d rather live in Osaka than Mobile.