Last fall, the euro zone settled on a fairly straightforward arrangement to quell its crisis. Member nations would cut their deficits through years of grinding austerity. In return, the European Central Bank would use its power to prevent a run on the bond markets.

Now that deal's being called into question. Yesterday, some 57 percent of Italians cast a vote against further austerity measures in the nation's parliamentary elections. A good portion of the vote went to former prime minister Silvio Berlusconi, who was promising tax cuts rather than increases, and comedian Beppe Grillo, who was advocating a boost in public spending.

Italians, it appears, aren't thrilled with the austerity-for-no-market-crisis trade. The country is already being squeezed by high taxes and stagnant growth, and many voters don't seem overly impressed by arguments that deficit-cutting and labor-market liberalization are the only viable options out of their debt mess.

So now we'll have to see how the rest of Europe reacts. Last year, when the Greeks prepared to vote the "wrong" way and reject austerity, countries like Germany started talking about booting Greece from the euro. Eventually, a plurality of Greeks caved and voted for politicians who agreed to spending cuts in exchange for aid from Europe. (Since then, the country's unemployment rate has soared from 23 percent to 27 percent.)

Another big question will be how Mario Draghi of the European Central Bank might respond if the financial markets began panicking about Italy. As Gavyn Davies explains, the only reason that Italy's public debt — now at about 125 percent of GDP — is currently sustainable is that the ECB has said that it will do "whatever it takes" to prevent Italian borrowing costs from soaring. That's now in question:

Until now, there has been another comfortable assumption, which is that the ECB balance sheet will be available, in extreme conditions, to prevent a “run” on the Italian bond market. ... The problem that now arises, though, is whether the ECB will be able to trigger OMT [its bond-buying program], and therefore hold bond yields down to levels that maintain that debt sustainability. ...

Mario Draghi has agreed to do “whatever it takes” to keep the euro intact, but does that include buying unlimited quantities of Italian bonds, backed by a government unable to accept a eurozone-style economic agenda in the country? If the Bundesbank is jumpy about France, just imagine what they will make of that situation in Italy.

So do Draghi and the European Central Bank start backtracking on their pledge to save the euro in order to put pressure on Italy? Or does the central bank try to avoid further panic at all costs? Tim Duy thinks that the ECB should do the latter. But he's not entirely sure that will happen:

I am very much hoping that the ECB will keep calm and not do anything that encourages market participants to once again doubt the central bank's commitment to the Euro. Otherwise, this spring and summer will look much like last year's. And the year before that. And the year before that.

Related: Everything you need to know about Italy’s messed-up elections