The Eurozone crisis that followed the Great Recession resulted from the structure of the Euro, which had removed the option for countries in the Eurozone to monetize their debt, creating a default risk, forcing them to inflict disastrous austerity on their economies and lengthening the recession.
While US states saw similar affects on their budgets (since they are not allowed to run deficits) this was offset by large federal deficits which kept the economy running. Borrowing costs were kept low by the Fed's QE.
EU central spending is only about 1% of GDP, much less smaller than the US Federal Government spending of 20% in normal years and does not borrow in its own right. The ECB's eventual agreement to stand behind Eurozone governments and pledging to buy their debt was crucial to resolving the crisis.
You like to see human agency in the resolution of the crisis.
In my opinion that's not the case, all the interventions and the tinkering of the unit of accounts and messing with the plumbing of the money markets has a neutral effect.
Wallace Neutrality and Miller-Modigliani prove this mathematically.
You also have to take into account the extreme worry if not outright panic that people have when they see the Fed resort to these sort of hail mary interventions.
"If they need to do this...how bad must it be?"
This was a recurrent theme during the GFC, so there's empirical evidence to claim it's not even neutral but actually counterproductive
Money is just a unit of account. But without enough of it the system gums up and people are left unemployed. We moved on from the gold standard for good reason.
While US states saw similar affects on their budgets (since they are not allowed to run deficits) this was offset by large federal deficits which kept the economy running. Borrowing costs were kept low by the Fed's QE.
EU central spending is only about 1% of GDP, much less smaller than the US Federal Government spending of 20% in normal years and does not borrow in its own right. The ECB's eventual agreement to stand behind Eurozone governments and pledging to buy their debt was crucial to resolving the crisis.