It may be a realistic option considering the alternatives promoted by the FMI-EU tandem. Anyhow, after the BB+ rating by S&P it will not make much difference.
BBC reproduces a demonstrator's opinion, a bank worker's one to be more specific:
We should opt for bankruptcy. Goldman Sachs, Deutsche Bank, Wall Street, they lent us the money. (Far better) they lose their money and people don't lose their jobs.
But the case is: can small Greece, with only 10 million inhabitants and not so many natural resources other than sunny islands for turism survive alone? How?
I have little doubt that the Greek people have the organization to go in revolutionary spree. They may be the only ones in Europe in fact in such excellent revolutionary conditions. But, even if they succeed, what then?
A more realistic case may happen in Iberia, a far larger area and next on the list for catastrophic FMI-dictated austerity packages. Iberia does not have such a large well organized class struggle as of now but, in the case it would, it could indeed hold a very viable economically autonomous area (Spain alone is right now the 9th global economy by GNP, holding 2.5% of the World's GDP (nominal), almost half of Germany's). Even in the case of international ostracism it can find some economic space working with Latin America, largely a red zone already, for example. Geographically closer Arab countries such as Lybia and Syria are also potential partners for any ostracized Mediterranean power.
Of course, there are two problems:
One is the tight rope of the euro, which should be in fact the main problem to address at pan-European scale (from a liberal perspective), devaluating it significantly in order to boost exports, reduce imports and secure jobs and public services. The North European gang, lead by German Capital, is however getting too many benefits from this situation and unable to react fast enough to to protect the system they have created for their benefit. The fact that Germany exports mostly to EU countries says it all.
The other is military intervention. If anyone believes that the Empire is going to let countries leave without intervening, he/she is of course very wrong. The first line is indeed the local armies and police forces, normally with strong right wing, fascist-like tendencies. But they can succumb to popular pressure and nationalist feelings. They can indeed also be defeated by political ways or their intervention trigger organization of guerrillas and such. The second line is direct military intervention by NATO (with similar or even worse results).
Whatever the case, the foresight for the next years is drastic increase of class tensions and possibly revolutionary changes (or alternatively anachronistic, and hence doomed, fascist attempts) in Southern Europe (among other places: the oven is very hot everywhere).
This situation would be unthinkable just a couple of years ago but now it appears as almost unavoidable. Thank Goldman Sachs and the other global bankers for this.
Next the sight stops on other even more sizable countries: Italy, France, the UK... none of them too buoyant. A very bad scenario is also ripe for Eastern Europe (Latvia is the most outrageous case but the rest are not well off either) and even Northern Europe (Iceland could not scape the voragine either).
Sooner than later, Germany itself will have to face the consequences of this global disaster. Best would be to act at European level but the EU building is frail and patchy, undemocratic and controlled by the big corporations. It's not an instrument of change but of continuity.
However class organizations should coordinate and direct the fights at this level, as the state level is obviously too limited to produce results. So far workers in Greece, in Latvia, in the UK, in Italy... are fighting separate battles against the same enemy. This may help the collapse of EU but is not really an effective way of struggle. We should see masses of people striking at Madrid, Paris and Berlin in support of Greek workers... but it seems that this people's facet of Europe has yet to be created.
It will eventually because nowadays state governments are very much powerless and irrelevant, so the action has to be taken at pan-European levels, if not at global ones. But this stage has not yet arrived and hence it's easier to witness a collapse of EU than a pan-European revolution. Still I'd prefer the latter, strongly so, and I think it is the way to go.