The fundamental problem is that the monetary systems of the modern world are all designed on the Wile E. Coyote principle. As long as you never look down, the system works. In the U.S. there is ~$14 trillion in government debt. There exists tens of trillion more in private debt. But only $2 trillion exists in bonafide, actual, real honest-to-goodness dollars (I'm including in that count accounts at the federal reserv…
Minor nit: I believe they adopted the current monetary system in anticipation of future political union. Which was not unreasonable, extrapolating from the Franco-German steel and coal pact forward to the subsequent treaty system that created the EU -- but it got stalled when they diverted into expansion (from 12-17 states to 25+) instead of consolidation in the late 90s/early 00s.
And they'd still have been okay, in the short term, if the entire global economy hadn't caught a head-cold in 2007/08.