Europe's banking crisis — and "crisis" is used advisedly — tells us how much and how little has changed since the onset of global financial turmoil in September 2008. Then, people worried about the viability of major American banks, loaded with "toxic" mortgage-backed securities whose value was difficult to determine.
Now, people worry about major European banks, loaded with government (aka "sovereign") bonds whose value is difficult to determine. We are flirting with another financial crisis not unlike the post-Lehman Brothers panic. This need not be.
In 2008, no one knew how government would respond to the siege of U.S. banks and financial markets, which couldn't raise the funds needed to support existing loans and investments. Now we know: Government — via the Federal Reserve and the Troubled Asset Relief Program (TARP) — provided the money to avert a complete financial collapse.