Why speculating against the Euro is dangerous

Today European Finance ministers met and the ECB has been stabilising countries where interest rates are higher by buying their governments bonds. These countries within the Euro zone have had higher unemployment and (in the case of Greece and parts of Spain and Portugal) more seasonal economies.
As such there is the option of further economic integration and debt stabilisation within the Eurozone but that would create a two tier Europe as the European Commission and Parliament could get democratic control of the Euro which would undermine the idea of european nation states sharing sovereignty and leave states without the Euro with less control over the European Union.
That is why the UK always seeks to meet its international obligations at the IMF and world bank and through that is stabilising the European and International economic system.

Yet the ECB can't buy back the bonds of governments within the Euro indefinitely