Greece's day of reckoning with bondholders dawns with economists from Barclays Capital to Deutsche Bank AG concerned that the world's largest debt restructuring will provoke aftershocks.

Eight months of negotiations reach a head with today's deadline for private creditors to accept a bond swap aimed at writing off 106 billion euros ($140 billion) of Greek debt. The government vows to bind holdouts to the deal should participation fall short of its target.

Possible repercussions include a surge in borrowing costs for other indebted nations as investors refuse to lend to countries that may follow suit in imposing losses on bondholders. The accord may also trigger derivatives designed to insure against default, and may not be enough to prevent Greece from reneging on its debts in the coming years.