LONDON — The global economy’s problems seem to be multiplying.
Hours after the leaders of the world’s 20 most developed economies sought to boost confidence by promising to increase global output by $2 trillion over five years, Japan said it had fallen into recession.
That leaves the country — the world’s third-largest economy — on a long and growing list of troubled economies. China is slowing as well, and Europe can’t seem to take off.
Among major economies, only the United States and Britain are growing at decent rates, and how long that lasts depends on how much trouble their trading partners are in.
British Prime Minister David Cameron warned in an opinion piece in the Guardian newspaper on Monday that the “red warning lights are flashing” for the world economy.
Japan Prime Minister Shinzo Abe had pledged to end two decades of stagnation with a strategy dubbed “Abenomics” that included big economic reforms and stimulus. But the economy contracted at an annual pace of 1.6 percent in the third quarter after housing and business investment dropped following a sales tax increase.
The contraction came despite predictions the economy would rebound from a drop in the previous three months.
Growth in China, a manufacturing giant, is slowing — from 10.4 percent in 2010 to an estimated 7.5 percent this year. China’s slowdown from high rates is echoed in many other emerging markets, such as India and Brazil.



