Greece as a country is relatively small potatoes, with its GDP ranking somewhere around 45th in the world at large, Greece hasn't been an economic force in centuries, yet Greece has been getting all sorts of publicity, because of its economic woes and civil unrest over the last few years and the fact this western nation's economic situation is dire. On virtually every economic level, Greece is in sad shape, with high inflation, high unemployment, and retraction of its GDP, along with its massive debt overload which it cannot service successfully. All of this, brought about not just domestic disturbances within the nation itself, but lead to the inevitable closing of the financial markets, so that those that needed to trade in the stock market, or to access a bank for cash or other financial transactions, were either completely shut out from doing so, or severely restricted in accomplishing things that previously were taken for granted.
The bottom line is that a severe financial crisis often has incredibly bad repercussions within a country, and depending upon the size of the country can possibly produce tragic ramifications throughout the entire world. For instance, the USA has currently a massive debt load of nearly $19 trillion dollars, but even that number as large as it is, is dwarfed by the possibility that including all of our off-budget legacy obligations that our true national debt could be as high as $70 trillion. The problem with massive deficits and the continuation of policies that keep increasing these deficits is that one day, some day, the creditors to these obligations such as financial institutions and foreign countries, may begin to doubt that ability of a nation, even one as rich and powerful as the United States, to make good on their debt.
There are hedge funds run by geniuses that have made huge amounts of money, understanding the markets, and taking advantage of obscure pricing differentials and inefficiencies between markets, that have consistently made money, until there comes that day, when the "black swan" event comes, that could not ever come, but it does and then this same hedge fund collapses within a very short period of time, because its house, far from being built on a solid foundation, has instead been built on assumptions that are good 99.99% of the time, when instead they needed to be good, 99.9999999% of the time, and with a viable contigent exit strategy, no less.
The fallout and collapse of Greece should be an object lesson to all that a country, any country, cannot successfully rely on the ever present availability of capital to paper over the deterioration of previous financial situations, ad nauseam. When the time comes that the lenders get wise to the game, or that the lenders decide that they wish to change the terms of the game, you, as a borrower, probably don't have a lot of good choices, and the lack of those choices, will be felt throughout the entire infrastructure of your country, when word gets out, that your credit line has been terminated or severely restricted.
As Shakespeare tell us, "Neither a borrower nor a lender be, For loan oft loses both itself and friend,
And borrowing dulls the edge of husbandry." Greece as a country cannot honor its debts, and by this dishonor, they have short-changed their citizens, their economy, their liberty, their livelihood, and ultimately their lives.