At the close of WW2, the US was the world's one economic powerhouse, with unmatched technology and a large portion of the world's manufacturing capacity. Wages and standards of living in the US were higher than anywhere in war-torn Europe (even Switzerland), far higher than in Asia.
But today the US has almost no manufactured exports, and we export agricultural products from plantation farms, much like a banana republic. Weapons are our only hi-tech export. 35 years ago, we went from the world's biggest creditor to the world's biggest borrower, and our debt has been growing exponentially ever since.
So, how is US wealth and prosperity maintained? It's because the dollar is the world's common means of exchange. We're in the business of printing dollars for other nations to trade with. How long can that privilege last, when we go around acting like a bully and making other nations hate us?