It is not just the Zeuro which is at risk of flailing and failing. The Zeuro's demise is a surety. It always was a political project which offended basic economics, natural currency formations, and trade and investment differences between the 27 Euro zone members. When the Euro fails it will presage at least 2 more economic downturns and massive wealth destruction. You can print all the colored paper you want to. Paper dikes won't hold back the flood of reality.
Fiat currencies will disappear at least in their current form. When Nixon abolished the Gold Standard in 1971 he did so for self-interested reasons. He was aping the failed but short term policy of Lincoln during the Civil War – print more money all the time – to fund the war effort. That lasted only 4 years, and the inflationary effects were real but eaten up within 5 years by a rebounding economy, growing large and powerful on a unified Continental sized market. Nixon's feat has endured 40 years with a huge increase in the printing of money aligned with zero interest rates in the past 10 years, guaranteeing some form of future financial destruction. There are laws of economics, and we can't ignore them, though the big brains which run the world often times do.
US debt took off post 1971, when the US dollar was decoupled from the Gold standard.
Once the politicians were 'freed' from the constraints of the Gold Standard all hell has broken loose. Welfare statism has run amok with programs aplenty for any and all. Half the population does not pay income tax, but it is usually that cadre of people who use the welfare state the most. Hence the unbreakable cycle of most socialism. More goodies, candies, and promises of security for the children. Once a program or a tax is created, the behemoth of bureaucracy ensures its expansion. Jubilee.
US bankruptcy is a distinct possibility. So the Zeuro zone is not the only economic actor at risk. The world's foremost consuming Republic is bent on self-immolation. Economists Carmen Reinhart and Ken Rogoff studied 29 nation state bankruptcies and the many factors which contribute to a repudiation of debts. In general a default on national debt owed occurred when the debt level surpassed 73% of GDP. This is quite a bit lower than Braudel's seminal work which put the number at 200% of GDP. In other words we are already at the edge of the financial cliff. If the Americans accounted for their debt properly by accruing off the balance sheet liabilities of $100 Trillion, such as Medicaid [bankrupt], Medicare [bankrupt] and Social Security [bankrupt circa 2025]; which GAAP mandates, than the real US debt figure is now $25 Trillion or 180% of GDP.
All modern welfare states are sick animals. Not only is a financial implosion going to happen, we have eviscerated our dynamic responsible culture and substituted state programs, security, guarantees and nanny-coddling. We have erected a society of individuals who never need to grow up. Witness Norway and Sweden with their effusive socialist state and the permanent adolescence of its citizens. They will also suffer when the Eurozone plummets. Norway is fat on oil. Sweden on exports to Germany. In other words the Europeans are transferring their meagre incomes to the Nordics in exchange for raw materials and some manufactures. But that will end when the edifice of modern socialism comes crashing down falling squarely on the middle class and lower income populations.