Until recently, the concern about Europe has been mostly theoretical--a potential train-wreck that would occur if/when the world's lenders decided that the continent's problems extended beyond the basket case known as Greece and cut lending to Europe's "core."
Well, that concern is no longer theoretical.
As a result, the borrowing costs of many European countries are rising fast. And so are inter-bank lending rates, because the second huge problem with the Euro-train-wreck is that Europe's banks have Euro debts coming out of their ears.
(When bond yields rise, the market value of existing bonds drops, so any bank that owns the debt of any European country is suffering huge embedded losses. The banks don't mark these losses to market, so you can't see them on the balance sheet, but they're there.)