In 1971 Nixon removed the USA completely from the gold standard. No longer is our currency tied to anything concrete, it becomes an abstract floating currency.
Sky is the limit for printing money, and other factors start determining its “worth”.
This bleeds around the world and has a name.
Couple this with the Economic Stability Act of 1970 (which surprise!! Did not do so well.) and the worlds economies - they depended a lot more in the US then than now - all suffered and continue to suffer to this day.