Via CNN:

Estonia is the only eurozone country with a budget surplus. National debt is just 6% of GDP, compared to 81% in virtuous Germany, or 165% in Greece.

Via the Wall Street Journal:

With the smallest total ESM [European Stability Mechanism—the permanent bailout fund] contribution after Malta and thus the fewest votes, Estonia could easily be overruled and forced to put up the cash against its will should the emergency voting measure come to pass. Its liability for the bailout fund could conceivably rise to as much as €1.3 billion, a small amount for the euro zone as a whole but almost 8.5% of the Baltic country’s gross domestic product and more than 20% of its 2012 state budget revenue of about €6.2 billion.

And so frugal, disciplined, post-Soviet Estonia could (conceivably) end up bailing out Spain.

It’s a rum thing, euro-zone “solidarity”.