The US has not had a real budget surplus for almost 60 years and has run balance of payment deficits every year since 1975. A country that lives above its means for over half a century is technically and economically bankrupt. Its debt should have zero value and so should its currency. But the US has skilfully avoided bankruptcy so far by having the reserve currency of the world and being the biggest military power.
https://goldswitzerland.com/follow-the-money-follow-china-russia-and-india/
