http://theeconomiccollapseblog.com/arch ... -in-europe
"So why is Greece so important?
Well, there are two reasons why Greece is so important.
Number one, major banks all over Europe are heavily invested in Greek debt. Since many of those banks are also very highly leveraged, if they are forced to take huge losses on Greek debt it could wipe many of them out.
Secondly, if Greece defaults, it tells the markets that Portugal, Italy and Spain would likely not be rescued either. It would suddenly become much, much more expensive for those countries to borrow money, which would make their already huge debt problems far worse.
If Italy or Spain were to go down, it would wipe out major banks all over the globe."