WASHINGTON – The fate of the global economy, European unity and ordinary Americans’ 401(k) savings hang in the balance as Europe’s leaders meet this weekend to try to resolve a burgeoning debt crisis.

European Union finance ministers agreed here Friday to pay Greece its next $11 billion installment of bailout loans, avoiding a potentially disastrous default. But Greece’s debts are only one piece of Europe’s economic puzzle.

The leaders are expected to decide at their European Union summit by Wednesday whether and how to expand the bailout fund they created this year.

They also must decide how to add cash to their faltering banks — in need of $100 billion to $300 billion — to prevent collapses or runs by nervous depositors.

That’s a full plate. So full that leaders of France and Germany, the pre-eminent powers of the 27-member European Union, will keep meeting into next week rather than finishing their EU summit Sunday, as planned.

Technically, EU leaders have pledged to reach some resolution before leaders of the world’s 20 most advanced economies — the G-20 — meet Nov. 3-4.

But investors across the globe are increasingly restless, and if EU leaders don’t make visible progress soon, financial markets across the globe could spiral down as soon as Monday.

There’s much more at stake in Europe than the debt woes of a few countries. Six decades of work to integrate European economies, which collectively include 500 million consumers and economic activity in excess of $17 trillion — more than the U.S. — could unravel.

“You’ve got a short-term problem, which is Greece … and a longer-term problem, where there are some serious structural and design flaws in the European Union,” said Nariman Behravesh, chief economist for forecaster IHS Global Insight.

For more than a decade, Europe has had a common currency, the euro, and monetary policy set by a single entity, the European Central Bank.

But each member nation has retained sovereign responsibility for taxation and spending. Many amassed huge debts.

Adopting a common fiscal system would require countries with millennia of history to cede their sovereignty to an EU bureaucracy. Proud citizens of each nation likely would object, which means the politics of democratic Europe could preclude the EU from taking the structural economic reforms it needs to survive.