I would have thought that the basis of the Greek crisis was very simple: they were allowed, perhaps even encouraged, to borrow more money than they had the income to repay. When world wide crisis hit because our nice American cousins had fiddled with the banking system to hide the fact that they had lent billion of dollars to people who didn't have the income to repay the Greek crisis was an unfortunate side effect. In the end the same applies to a country as it does to a private person. The only difference is that Greece is being kept afloat to avoid it defaulting on its debts to the banks.
Then the US government let a couple of banks sink to the bottom of the bay, prosecuted a couple of people, and then propped up their banking system with loads of cash. This allowed the top executives to collect their bonuses and the rest has been swept under the carpet with no compensation for the banks in other parts of the world who had been nearly bankrupted by the bad faith of the US banks.
Sure there are many other reasons for the current economic crisis but in the end it is you and I that are paying for the saleries and bonuses of the fat cats in banking and politics.
The economists can fill it up with as many technical terms as they like but in the end it is the greed and manipulation of the rich and powerful (not all rich and powerful, thank goodness) that we ordinary people pay for.