Greece didn't do this on its own. I can't find the Krugman column showing that Greek debt levels weren't too outside the norm pre financial crisis. So I'll post this:
http://mobile.nytimes.com/2015/06/29/op ... &referrer=
European Central Bank and IMF imposed austerity caused the current crisis, not Greece.
And Greece's inability to inflate to get out of the liquidity trap has forced its hand. Germany is holding a gun to Greece's head to enact its own ideological agenda.
And I want to add in an edit that Europe is endangering the whole world economy through its actions. Screw the banks. Make them take a hit. Save Greece!