Hi, IMHO a really great question.
My comments:
a) By force isn't going to happen. The EU integration was about preventing wars by greater integration, especially economics.
b) That is probably where the EU is heading in many, many years to come... but not now.
c) I doubt any of the lenders want to throw anymore good money after bad.
So yeah... what the heck to do?
I really hate to say it but that leaves only two things Greece can do:
1) Greece has to leave the Eurodollar but is still a member of the EU, or
2) Greece leaves the EU completely (including the Eurodollar), and
...only one thing the creditors can do:
1) Extend better repayment terms.
So why would I suggest the above? Well for one thing the reason the UK is doing well economically is because the Bank of England has greater control over fiscal and monetary policy AKA the UK still has the pound (GBP).
My take on things is that Greece won't get out of this mess until they get a handle on fiscal and monetary policy and the main way to do that is by controlling your own national currency.
Also to my knowledge no Government has ever been allowed to go 'Bankrupt'. Essentially fiat currency is backed on the tax intake of a nation... but in the case of the EU... on the tax intake of the entire EU block.
There is some German poster who got down voted on what seems like the basis of a negative stance on Greece's predicament, however by linking all the currencies together the German politicians were tacitly agreeing to back Greece. Therefore IMHO it's not wholly Greece's fault that this mess got this far... the ECB and EU member nations should have tightened things up but then again France, Spain and Portugal are basket cases as well. And don't get me started on the fact that the EU's books aren't even audited... never the less, the point I was making is that it seems like the mood in the EU is to stop supporting Greece financially which means that Greece needs it's own currency again.
And I don't just say this matter the factly... what I'm suggesting will have huge ramifications and destroy lives, families, businesses--it's be total economic chaos until the market can sort itself out again (because by linking the different currencies together the market has been allowed to distort).