FLORENCE -- The decision to suspend Greece from the common currency became inevitable when it emerged that Athens had fiddled with the accounts yet again amid chronic economic weakness, forfeiting what credibility in the international arena it still had left.

That was in 1908.

After diluting the gold content in its coins, Greece left the Latin Monetary Union, whose founding members included France, Italy, Belgium and Switzerland. More than a century later, history may repeat itself, albeit in vastly different circumstances.

From the dual currency economy of 14th-century Florence to the monetary union of Austria-Hungary and Argentina's abandoned dollar peg, the past is littered with examples of countries' weighing the costs and benefits of different monetary regimes....