Japanese debt

It's true that the U.S. has racked up the largest debt of any developed country. But when you consider the debt in relation to the country's gross domestic product, it's only No. 7 on the list, according to Fortune. Here's what you need to know to make sense of all the numbers.

An 8.9 earthquake rocked Japan to its core, rattling businesses with operations in the affected areas. But the epicenter's distance from Tokyo saved many businesses from the worst of the damage. Could one of the aftershocks be an economic stimulus for the debt-ridden country?

Fueled by a high domestic savings rate, Japan piled up debt to epic levels over the last few decades. But as its population ages, the days of cheap debt are coming to an end -- and the global economy will feel the effects.