After months of fragile economic growth, fears are mounting that the global recovery could be derailed by a debt crisis that began in one small corner of Europe.
At first investors voiced only mild concern about events in Athens. News that Greece had fiddled deficit figures did little except increase the country's cost of borrowing and raise eyebrows at the European Union's Brussels headquarters.
But as world stock markets were pummelled in recent weeks and the euro fell sharply against the dollar, that concern has given way to scarcely concealed panic.
Respected commentators are beginning to echo the twitterverse's shrill warnings that a once- obscure debt problem could prompt another Great Recession.
If a €750 billion EU rescue package fails to calm markets, "US GDP growth could be reduced by half to one per cent over the next couple of years," Deutsche Bank analysts warned clients.
"If the rescue programme fails altogether, we are looking at a potentially much more negative picture, with the distinct possibility of a double-dip recession."
Greece, with debt of nearly €300 billion, agreed this month to spending cuts and higher taxes in exchange for a €110 billion bail-out package from the European Union and the International Monetary Fund.
Still, with another crisis looming, experts point out that the downturn's symptoms look eerily similar to the last one, with nods at the financial system and banks in particular.
Daniel Tarullo, a member of the Federal Reserve's board, recently suggested a repeat of the 2008 crisis that saw the near collapse of the US financial sector was "not out of the question".
"One avenue through which financial turmoil in Europe might affect the US economy is by weakening the asset quality and capital positions of US financial institutions," Mr Tarullo told Congress last week.
Banks, he said, were going through spasms that "brought back memories of developments during the recent global financial crisis".
Then, faced with doubts about the health of competitors' balance sheets, banks began closing down credit lines, sparking a domino effect throughout the financial system.
The fear is that banks will again stop trusting each other, according to Uri Dadush, a former director of international trade at the World Bank who is now with the Carnegie Endowment.
"Even though US bank exposure is relatively limited the banking systems in Europe and the United States are so interconnected, and European banks have a lot of exposure," he said.
The top 10 US banks are estimated to hold around $60 billion in debt from "peripheral" European nations, around a tenth of their principal capital.
Their banking counterparts across the Atlantic, particularly in France and Germany, have much more significant exposure.
The gap between inter-bank borrowing costs in Europe and the United States has exploded in recent months, which analysts say is a sign of growing concern.
"Broader recovery concerns and potentially elevated counterparty credit risk could be the main drivers," said Geoffrey Yu of UBS.
"Either way, investor concerns have expanded from beyond the eurozone into a broader arena."
As if to underline the concern, stock markets around the world were weighed down on Monday by news that the Spanish government was forced to bail out CajaSur, a local savings bank.
Trade may also be hit.
As the euro was pummelled by investors, US and Asian exports have become more costly for Europeans, who many fear will be able to buy less as the recovery slows.
Around a quarter of US manufacturing exports go to Europe. The sector employs an estimated 11.6 million Americans.
Ironically, the single European currency's fall in value may make Europe more competitive, boost exports and offer the continent an exit from the crisis.
"The euro devaluation can help," said Mr Dadush. "A 20 per cent devaluation of the euro is a big deal, but everyone has to realise that the benefits of the devaluation are going to be spread quite unevenly."
Regardless, a crisis that began with dodgy accounting now looks a whole lot more serious.