Southern Europe has not done enough to enhance its competitiveness, while northern Europe has not done enough to boost demand. Debt burdens remain crushing, and Europe's economy remains unable to grow.

The consequences of a collapse would not be pretty. Whichever country precipitated it - Germany by threatening to abandon the euro, or Greece or Spain by actually doing so - would trigger economic chaos and incur its neighbours' wrath.

The 24% unemployment reached at the depths of the Great Depression was no picnic.

More than the Big Mac, Coca Cola, or Levi's 501 jeans, the dollar is surely the United States' signature export.

For those unfortunate enough to experience it, long-term unemployment - now, as in the 1930s - is a tragedy. And, for society as a whole, there is the danger that the productive capacity of a significant portion of the labour force will be impaired.

Political union means transferring the prerogatives of national legislatures to the European parliament, which would then decide how to structure Europe's fiscal, banking, and monetary union.

Southern Europe has not done enough to enhance its competitiveness, while northern Europe has not done enough to boost demand. Debt burdens remain crushing, and Europe's economy remains unable to grow.