Put all of this together and there is a very real possibility of trouble.

China has had a 30-year run of stellar economic growth. But it’s only human nature for such expansion to breed too much optimism, overextending an entire economy. Americans have found this out the hard way in their own financial crisis.

History has shown that no major economy has grown into maturity without bubbles, crises and possibly even civil strife or civil wars along the way. Is China exempt from this broader pattern?

The notions of excess capacity and malinvestment were common in business-cycle theory of the 19th and early 20th centuries, when growing Western economies had frequent crashes of this kind. Numerous writers, from the Rev. Thomas Malthus to the Austrian economist Friedrich A. von Hayek, warned about the overextension of unprofitable capital deployments and the pain from the inevitable crashes. These writers may well end up being a guide for understanding China today.

What will the consequences be for the United States if and when the Chinese economic miracle encounters a major stumble? A lot of Chinese business ventures will stop being profitable, and layoffs and unrest will most likely rise. The Chinese government may crack down further on dissent. The Chinese public may wonder whether its future lies with capitalism after all, and foreign investors in China will become more nervous.

In economic terms, the prices of Chinese exports will probably fall, as overextended businesses compete to justify their capital investments and recoup their losses. American businesses will find it harder to compete with Chinese companies, and there will be deflationary pressures in both countries. And even if the Chinese are selling more at lower prices, they may be taking in less money over all, so they may have less to lend to the United States government.

In any case, China may end up using more of its reserve funds to address domestic problems or placate domestic interest groups. The United States will face higher borrowing costs, and its fiscal position may very quickly become unsustainable.