As it seems to me, though, you have 15 nations or so that all use Euros. Currencies, like stocks, are bought and sold, depending upon their shrinking or increasing value, which is a function of relative rates of inflation. Now, this applies to both the currencies, and to any investments offered in those currencies.
Despite having a common currency, the individual European nations do their own taxing, and their own spending. Half of Europe has decided to spend far more than they tax. This of course creates problems. Greece in particular has the further problem that it is ADDICTED to all the things that come from having your parents Platinum Amex. You spend the money, and somebody else pays the bill. Not your problem.
Now, the economic disaster everyone keeps warning about, for Europe, is that somebody is going to go broke. When they go broke, all the bonds issued by their government will become worthless. That is what going broke means: you stop paying your bills.
Now, this means that the Euro as a WHOLE could collapse in value. This means that those banks that are currently financing the lifestyles of the poor and frivolous will stop making those investments. Greece goes bankrupt, but then Spain and Italy can no longer borrow money. This is why they are talking about “eurobonds”, which is to say bonds that in effect are backed by serious people who keep tight books, and who can be expected to pay for the spendthrift ways of their profligate brother nations. This in effect rewards fiscal profligacy, and if the past is any indication will do nothing at all to curb the fundamental irresponsibility of these nations that think you can do close to no work and live like a rich man.
Unless and until the entitlement mentality of the PIIGS can be dealt with, there is no hope that the overspending and following problems will end.
As I see it, unless the juveniles in southern Europe can be convinced to grow up, the only credible option for those who do not want to support them forever is to figuratively (and literally) boot them out of the house.
The irony, of course, is that the EU is a Socialist project, one intended to work towards a unified world government, under the nominal control of the UN, and the actual control of the global bankers–particularly the Central Banks. ALL of these nations are trying to implement socialism. They are all trying to use the power of government to eradicate poverty and provide social equality. They have just failed prematurely. One legged stools do that, though, the moment someone stops holding them up.