Greece, somehow has bamboozled the EU into giving them handouts. After being allowed into the Euro back in the 1990's, the Greeks managed to paper over their humungeous deficits by floating bonds. Somehow, a bunch of sucker banks, mostly in Germany, was stupid enough to buy the bonds, thinking that they would get paid back on time. The Greeks kept the illusion going by using the proceeds of the latest bond sales to the roll over old bonds.
This scam finally unraveled and every one, even the sucker banks, stopped buying Greek bonds, or making loans to Greece. At this point, the Greeks owned so much money, that allowing them to default would cause intense pain thru out Europe. The sucker banks cried that a Greek default would bankrupt them. So, the EU decided to bail the Greeks out, a bit. They demanded that the Greeks clean up their act, balance their budget, lay off the enormous number of Greeks on the Government payroll, and tighten up tax collection. In return for promises to reform, the EU would give the Greeks enough money to pay the interest on their debts. Which means that the sucker banks can carry their Greek loans as assets on their books. If the Greeks stop paying, then sooner or later, the sucker banks would have to declare a whacking big loss. A loss big enough to put a number of them out of business.
This stop gap situation may come unraveled this spring. The Greeks have to hold national elections and the polls all show a new populist party Syrisa about to win outright. Syrisa is threatening to scrap all the promises of reform, and stop paying on Greece's foreign debt. At which point the EU handouts will stop.
What happens to the EU and the Euro is unknown, but the Europeans are worried about it. The Greeks will have to figure out how to live within their means. They may decided to drop out of the Euro so they can print their own money, as much as they need, to meet payroll. They may not, because all Greeks with any kind of money, in Euros, will be against the idea. Dropping out of the Euro, would mean everyone's Euros would turn into Drachma, and then the Drachma would drop 50% or more against the Euro. In effect, every Greek gets a real close haircut. No one wants that.