It's all due to the debt spiral
Increasing global indebtedness will generate new crises. The euro "debt" crisis was another episode of the global financial crisis, which itself was a debt crisis. European governments had to rescue private agents. Private debt became government debt. The euro area was not prepared for that... The global debt spiral forces central banks to print money and buy debt. This generates risks for the monetary system in a world of debt that has lost direction, credibility, and solvency...  

The Dangerous Power of Hystery
It cannot be excluded that during the euro crisis the timing and intensity of simultaneous austerity measures in Europe had been motivated by market hystery rather than by rational analysis. Since then, long recessions and increasing youth unemployment have laid the ground for radicalism and euro scepticism.

Italy more sustainable than thought?