Indeed, the debt crisis that is brewing today may result in the break-up of the Eurozone /Eric Knight, FT, Market Insight, 11 June 2021/.
The EU and the Eurozone had five major crisis before the present Covid-19 pandemic / around 2000, between 2007 and 2009, in 2010, in 2011-12 and the migration crisis in 2015/. All these five calamities worked against the deeply-rooted European concept that a crisis strengthens European integration. The EU and the Eurozone got out of all the five shocks weaker than they were before.
In the 2020s we can expect multiple crisis, partly repeating the 1970s. All coming crisis will have the same results than the last five shocks.
The looming next financial crisis might contribute to the Eurozone breaking into two blocks or they will copy the Japanese way piling up ever bigger debts.
We can also have a mixture of these two outcomes.
Governor Matolcsy, MNB, the Central Bank of Hungary