And the factories are important, for China and everyone else. Someday China may matter internationally mainly for the nature of its political system or for its strategic ambitions. Those are significant even now, of course, but China’s success in manufacturing is what has determined its place in the world. Most of what has been good about China over the past generation has come directly or indirectly from its factories. The country has public money with which to build roads, houses, and schools—especially roads. The vast population in the countryside has what their forebears acutely lacked, and peasants elsewhere today still do: a chance at paying jobs, which means a chance to escape rural poverty. Americans complain about cheap junk pouring out of Chinese mills, but they rely on China for a lot that is not junk, and whose cheap price is important to American industrial and domestic life. Modern consumer culture rests on the assumption that the nicest, most advanced goods—computers, audio systems, wall-sized TVs—will get cheaper year by year. Moore’s Law, which in one version says that the price of computing power will be cut in half every 18 months or so, is part of the reason, but China’s factories are a big part too.

Much of what is threatening about today’s China also comes from its factories. Many people inside China, and nearly everyone outside, can avoid the direct effects of the country’s political controls. It is much harder to avoid its pollution. The air in Chinese cities is worse than I expected, and because the pollution affects so many people in such a wide range of places, it is more damaging than London’s, Manchester’s, or Pittsburgh’s in their worst, rapidly industrializing days. The air pollution comes directly from the steel works, cement plants, and other heavy-industry facilities that are helping the country prosper, and indirectly from the electric power plants that keep everything running. (Plus more and more cars, though China still has barely one-thirtieth as many per capita as the United States.) The sheer speed and volume with which factories and power plants across China increase their output of soot and gases make the country’s air-pollution problems the world’s. The heightened competition for oil, ore, and other commodities to feed the factories affects other nations, as do slapdash standards of food purity and safety, which may have led to tainted worldwide supplies of animal food. The ultimate fear in the developed world, of course, is that as China creates millions of new factory jobs unknown millions will lose such jobs in America, Canada, Germany, even Japan.

But these factories are both surprising and important in a less obvious, though also fundamental, way. Almost nothing about the way they work corresponds to the way they are discussed in the United States. America’s political debates about the “China opportunity” and, even more, the “China threat” seem distant, theoretical, and imprecise from the perspective of the factories where the outsourcing and exporting occur. The industrialists from the United States, Europe, or Japan who are deciding how much of their production to move to China talk about the process in very different terms from those used in American political discussion. One illustration: The artificially low value of China’s currency, relative to the dollar, comes near the top of American complaints about Chinese trade policy. (The currency is the yuan renminbi—literally, “people’s money”—or RMB). This is more like the eighth or tenth issue that comes up when business officials discuss the factories they are opening in one country and closing in another. And when it does come up, the context is usually whether the RMB’s rise will force a company to put its next factory not in China’s crowded coastal region but someplace with even lower costs, like the remote interior provinces, where salaries are lower and commercial space is cheaper—or perhaps Vietnam or Cambodia.