The level of naïveté displayed in this comment is shocking.
America is politically able to let, for example, Detroit, die a lingering death. For obvious reasons the Greeks would rather a similar fate wasn't in store for their country.
"Damned if you do, damned if you don't" as a famous early 90s child philosopher put it.
https://en.wikipedia.org/w/index.php?title=Articles_of_Confe...
States, despite all this fanciful nostalgia, do not exist in a vacuum and their continued sovereignty today is dependent on belonging to a larger unions. It's the only way to protect themselves from the imperialism of powerful federal unions like the US, Russia, and China. If any European state thinks that it can exist independently of a federal (or worse) arrangement, it has misunderstood 20th century history.
And I would also argue the election of Trump demonstrates that you actually can't allow Detroit and similar regions to wither without significant political repercussions. The Democrats tried that and it cost them the election.
The shared attachement to democracy, peace, to solidarity versus exacerbated nationalism, refusing death penalty, of some version of social democracy in the broad sense of the term, is much stronger than what divides us.
except they never had this - the richer countries see their contribution as a drain (e.g., the almost collapse for the greeks), unlike the american state, which distributes the federal taxes somewhat more "evently", and there's no "Us vs Them" mentality.