Global financial systems will be doomed to repeat the 2008 financial crisis if policymakers fail to tackle the European debt crisis now, says Robert Zoellick, outgoing president of the World Bank.

The 2008 collapse of Lehman Brothers sparked a worldwide financial crisis, and a messy Greek exit from the eurozone could pressure larger countries to follow the same path, which would involve large-scale defaults that would rattle markets in Europe and elsewhere.

"Events in Greece could trigger financial fright in Spain, Italy and across the eurozone. The summer of 2012 offers an eerie echo of 2008," Zoellick says, according to The Daily Mail.

Editor's Note: Startling Proof of the End of America’s Middle Class. Details in the Video

"If Greece leaves the eurozone, the contagion is impossible to predict, just as Lehman had unexpected consequences."

While Greece is currently able to tap bailout funds, fears are building that the larger Spain may need help also, as debt-laden Madrid is set to recapitalize a large financial institution and may need to help regional governments refinance their debts.

Spain may sell sovereign bonds to prop up its banking sector and regional governments, but that might not be enough.

"Eurozone leaders need to be prepared to recapitalize banks. In the eurozone, the guarantees of some national sovereigns are unlikely to be sufficient and only that of the 'euro-sovereign' will suffice," Zoellick says, referring to calls for all countries to underwrite a single bond to shore up the continent's financial system a whole.

Policymakers in wealthier countries like Germany oppose such a plan.

"It is far from clear that eurozone leaders have steeled themselves for this step. Eurozone leaders need to be ready. There will not be time for meetings of finance ministers to discuss the outlook and debate the politics," Zoellick says.

Spain is preparing to bail out the Bankia financial institution, similar to Belgium's rescue of Dexia in 2011.

European Central Bank President Mario Draghi said recently the continent needs to create a centralized body to handled propping up banks, as individual regulators tend to wait until the last second to act and exacerbate the debt crisis.

"What Dexia shows — and Bankia shows as well — is that whenever we are confronted with the dramatic need to recapitalize, if you look back, the reaction of the national supervisors... is to underestimate the problem, then come out with a first assessment, a second, a third, fourth," Draghi told the European Parliament in Brussels, according to the Associated Press.

"That is the worst possible way of doing things, because everybody ends up doing the right thing but at the highest possible cost and price."

Editor's Note: Startling Proof of the End of America’s Middle Class. Details in the Video