Honestly, that was a toungue in cheek question. This was encountered more recently here: https://www.imf.org/external/about/histdebt.htm https://www.imf.org/ext

Honestly, that was a toungue in cheek question. This was encountered more recently here: https://www.imf.org/external/about/histdebt.htm https://www.imf.org/external/about/histdebt.htm The answer last time was global recession. Mainly because there was no alternative to USA and Soviet Union (which was crumbling). Third world countries were used as pawns. This time though, most other countries have solid institutions of their own. More likely, they will unite and start trading with each other in other currencies, gradually reducing dependence on dollar and trading with the US. The bitter truth about the world is that the US was a hero in 80s and 90s. Today, it's a toxic material that everyone deals with simply because of petrodollar.