From a currency area / international trade POV it's about the fundamental problems of having a common currency used among countries who have no common fiscal po

From a currency area / international trade POV it's about the fundamental problems of having a common currency used among countries who have no common fiscal policy[1]. If Greece and Germany had their own currencies, the exchange rates set by the free forex markets would have fixed many of the curernt problems and their trade balances would be neutral, but instead Germany has been running high trade surpluses and Greece has had high trade deficits (leading to debt) due to how the euro floats, and the central bank interest rate instrument is blunt and applies equally to all currency union countries. See eg https://archive.nytimes.com/krugman.blogs.nytimes.com/2012/06/24/revenge-of-the-optimum-currency-area/ https://archive.nytimes.com/krugman.blogs.nytimes.com/2012/0... for some history of how this wasn't really unexpected. Interestingly in that article higher inflation is seen as a potentially promising tool: "[T]he burden of adjustment might be substantially less if the overall Eurozone inflation rate were higher, so that Spain and other peripheral nations could restore competitiveness simply by lagging inflation in the core countries" [1] The EU budget is tiny compared to national budgets (or eg federal budget in the US), < 3% of the EU GDP.