Will an ever feebler currency save or sink Japan’s economy?

T HE LAST time the Japanese yen dipped below 130 to the American dollar, in 2002, China’s economy was smaller than France’s, Vladimir Putin was meeting Western officials with a smile, and Eminem, a rapper, was atop the pop-music charts. The yen’s slide to that abyss, first reached on April 28th and then every day since, has been precipitous: it stood at just 115 to the dollar at the start of this year. Japanese policymakers have begun to fret, leading markets to speculate about whether they will intervene to halt the fall. That would probably prove futile: deep forces are driving the yen’s depreciation.