The problem we are seeing is not confined to Greece, nor just to the PIIGS,* nor even to Europe. Too much of the world, including the USA, is living on borrowed money and, consequently, borrowed time. Savings rates in most Western countries (and most third world countries, too) are too low because most people and the governments they elect are spending too much too fast on non-essentials. We have moved beyond being happy to have our votes bought with our own money to expecting our votes to be bought with someone else's money - Chinese money, mainly.
There is essential spending - including essential public spending, which includes but is not limited to defence and a few others. Sometimes some essential services must be provided by the government, sometimes essential services are best provided by government, sometimes governments should contract out some essential services. The key point is that we should fund only essential services. The problem is that the people get very, even violently unhappy when they learn that 'free' public pensions and 'universal' and 'free' health care are not essential services but the national defence and paying the interest on the debt are.
Blood on the streets, as in Athens, will become more and more normal in more and more cities as the economic chickens come home to roost - not just in Greece, either.
--------------------
* Portugal, Italy, Ireland, Greece and Spain