Ah, so now we have it. The government is no longer forming a (nearly nonexistent) safety net for the banks - the same banks that make risky investments on purpose, overextending themselves and keeping little money actually in hand so they can make more money, and then depend on the taxpayer when they inevitably begin to fail.
"It is the fear that governments may not ride to the rescue that seems to have unnerved markets."
The fact is that, if banks would make better business decisions, they would have nothing to worry about. If they would just learn to say "no" when a risky investor came along, they would get into far less trouble. Sadly, the profit motive is too much of...well, a motive. But I see no reason why they shouldn't pay the price.