As detailed here:
https://www.zerohedge.com/contributed/2012-10-22/three-things-investors-dont-know-about-europe
Europe is an economic time bomb, with most of the major players having disturbing debt to GDP ratios. For example, Germany is conventionally cited as having 75 percent as its debt to GDP ratio, but according to Axel Weber, the head of Germany’s Central Bank, Germany has a  real debt to GDP ratio of over 200%.

     Jagadeesh Gokhale of the Cato Institute published a paper in 2009 claiming Germany’s unfunded liabilities are in fact closer to 418%, so one could imagine what it really is today.

     The article goes on to point out that financial institutions’ gross debt as a percentage of GDP is even worse:
Country -- Financial Institutions’ Gross Debt as a % of GDP
Portugal -- 65%
Italy -- 99%
Ireland -- 664%
Greece -- 210% ??
Spain -- 113%
UK -- 735%
France -- 148%
Germany -- 95%

EU as a whole    148%
Source: IMF

     The European financial institutions have more debt than the entire GDP of Europe, which means, by definition, that they are unsustainable. Collapse is inevitable:
https://www.forbes.com/sites/oliviergarret/2017/03/01/an-investors-guide-to-the-collapse-of-the-european-union/#36b2e4e4f805
https://www.express.co.uk/news/politics/844970/European-Union-German-economist-predicts-EU-euro-collapse-Brexit