It's quite simple really:
1. Almost all countries follow a socialist model
2. The model is deeply flawed as it expands entitlements to the non-productive and increasingly taxes the productive
3. The productive leave or become non-productive themselves (after all, what's the point?)
4. The model is unsustainable as revenues decrease, taxes become confiscatory, the black market flourishes and the dependent classes (almost everyone) blames the government for failing to continue to provide "their" (unearned) benefits
Greece is merely an early indication of the fate of the rest of Europe. And the US? California (state w/ the highest taxes) is bankrupt, other large states (NY, MI) are following suit and we have a President who is enchanted with a model that just does not work.