Get ready for it: Another economic collapse is coming.

[ProSense]

15. I don't

If the Greece withdraws from the EU, the Euro is finished.

That's the most likely scenario that would qualify as a "major European crisis".

...think that's what Krugman meant.

Killing the Euro

<...>

So the next time you hear someone claiming that if we don’t slash spending we’ll turn into Greece, your answer should be that if we do slash spending while the economy is still in a depression, we’ll turn into Europe. In fact, we’re well on our way.

http://www.nytimes.com/2011/12/02/opinion/krugman-killing-the-euro.html

On edit: I misread this point:

The Volcker rule is an important safeguard against the sort of speculation that imperiled commercial banks, but the fact remains that the flashpoint for a future crisis likely will not be in the United States.