In Europe, banks are facing funding difficulties amid concerns about their exposure to unpayable government debt.

FORBES: Barclays Sees Global Econ Heading On "Treacherous Path"

Mexico swaps its old, unpayable debts, for new debts with lower interest rates and smaller principal sums.

BBC: The state of play in Athens

It was entirely feasible that, perhaps 12 months ago, Greece could have defaulted on its unpayable debt and nothing much else would have changed.

FORBES: Eurozone: Sovereign Debt Becomes a Credit Crunch

Bold adjustment, which to its credit the new Greek government has already begun, will reduce the risk of Greece finding its debts unpayable in three years' time.

ECONOMIST: Greece's debt crisis

Short term debt is constantly rolled over when deemed unpayable.

FORBES: How Scary Is China's Shadow Banking System?

But soon it will be unpayable.

ECONOMIST: Brazil��s pension system