Italy took another step toward triggering a massive European economic crisis.

On Sunday, the country held a referendum on constitutional reform. It was rejected—nearly 60 percent voted no.

Prime Minister Matteo Renzi staked his political future on the vote. When the exit polls showed the reform was rejected, Renzi stuck to his word and resigned shortly after polls closed.

At first glance, the situation has nothing to do with the euro. The trouble is, Italy’s economy is a disaster waiting to happen. Any time there is an unusual political or economic event, everyone wonders, Is this the one that will make the whole thing explode?

Italy’s unemployment rate is at 12.4 percent, more than double Germany’s 4.2 percent. Youth unemployment in Italy is a staggering 40 percent. Its economy is barely growing and is nearly 10 percent smaller than it was before the 2008 economic crisis. Its industrial output is the same level that it was 35 years ago.

All this is causing massive debt trouble. Around 17 percent of loans by Italian banks—amounting to $385 billion—is not being paid back.

All of these longer-term problems became more immediate after Donald Trump’s electoral victory. Due to Trump’s promise of massive spending, investors have been selling government bonds from a variety of nations. The total value of government bonds around the world has fallen by over a trillion dollars—the biggest bond sell-off in over three years. Italy’s already shaky banks have lost a huge amount of money on the $428 billion of Italian government bonds they owe. Money has been pouring out of Italy—a trend that has accelerated in recent months.

“The contours are worse than the 1930s,” wrote the Telegraph’s international business editor, Ambrose Evans-Pritchard. “It is a lost decade turning into a second lost decade. No large developed country in modern times has ever suffered such a fate.”

It’s no wonder markets are nervous. Shares in major Italian banks dropped around 5 percent on Monday morning. The euro hit its lowest level since March 2015.

But an immediate crisis seems unlikely, which is why the euro quickly rebounded (though expectations of an intervention from the European Central Bank certainly helped). Italy’s electoral law is stuck halfway through reform. Parts of it were changed—in the assumption of a “Yes” victory. That needs to be straightened out before the country can hold new elections. In addition, Italy also needs to set its budget for 2017. The general consensus is that Italy’s parliament will approve a caretaker government to manage these immediate needs, and then hold an election in several months.

Even so, there is still the risk that the additional uncertainty could upset the already shaky banks.

Beyond that, once the elections hit again, the favorite to win is Beppe Grillo and his euroskeptic Five Star Movement, an upstart party founded in 2009 that managed to take third place last election. This time, polls put them neck and neck with Renzi’s ruling Democratic Party for the lead.

This crisis puts Italy at real risk of leaving the eurozone. And Italy is not Greece. It is a G-7 economy, a founding member, and part of Europe’s cultural heart. A QuItaly would shake Europe many times harder than a Grexit or even a Brexit.

But QuItaly may be the only way out. The European Central Bank’s (ecb) quantitative easing (QE) is the only thing keeping Italy’s banks afloat. Europe’s QE has become even larger than America’s. It has bought €1.4 trillion (us$1.5 trillion) of eurozone bonds worth 14 percent of the eurozone’s economy.

Germany never wholeheartedly endorsed QE, and now it looks like it has had enough. “ecb policy is threatening the European project as a whole for the sake of short-term financial stability,” said David Folkerts-Landau, the chief economist of Deutsche Bank. Germany may not get its way immediately, but it will be looking to end QE any chance it gets.

Furthermore, the ecb is limited in the number of Italian government bonds it can buy. It just bought a large amount to stabilize the economy after the vote. It doesn’t have much ammunition left.

Whatever happens, QE cannot last forever. Without a rescue program, Italy’s banking sector will sink. “There is no plausible way out for Italy within the current contractionary structure of monetary union,” wrote Evans-Pritchard. “Only ecb bond purchases forever can keep the lid on this pressure cooker.”

These, then, are the options Italy faces. Without European help—and even possibly with—Italy is heading for a banking crisis. Unlike the Greek crisis, Italy’s would be far too expensive for Germany to easily contain. It would threaten the survival of the euro and the German economy itself.

Another option sees Italy revolt against the euro. Outside the euro, with its own exchange rate, Italy certainly had many problems, but it was able to sell its goods at much cheaper prices that it can now. Its trade and economy did far better. But QuItaly would be traumatic, both for Italy and the rest of the eurozone.

The only other option makes Italy forever dependent on help from the ecb and, ultimately, Germany. This cannot go on forever. Germany would not tolerate it for long without concessions, and Italy would not tolerate those concessions for long.

Thus Italy is heading for a crisis. Each of these major pieces of news leads us to question: Is this the big one?

This could be that big one.

The troubled Banca Monti dei Paschi di Siena—the world’s oldest bank—needs to raise more money this week. A failure could easily trigger trouble.

The euro crisis has been going for eight years. We’ve seen crises flare up in Greece, Portugal, Italy, Spain, Ireland, Greece and Greece again. With each crisis, European leaders have found a way to get around the immediate problem without fixing the root causes. How much longer can they avoid those causes?

Italy, because it is much more central to Europe and far bigger than Greece, Portugal or Ireland, could be the one to provide the final, definitive crisis.

Such a crisis would shake Europe, Germany and, ultimately, the world. It would force Europe to either set aside the EU, the foundation of so much of its modern politics and economy, or complete the journey to a superstate.

This is why the Trumpet has been watching the crisis right from the start. A European superstate has been one of our longest-standing forecasts. An economic crisis could bring this about quickly.