China's open-market reforms, begun a quarter-century ago, launched an unprecedented social experiment. Never in modern history has there been a truly enduring technological and economic world power that wasn't a democracy—a free economy without free speech.

For the experiment's first 15 years, the Chinese government had no trouble keeping a firm grip on the reins of the news media. Then came the Internet. Could the government open the floodgates to the waves of information washing up on every shore yet keep out the ideas it was afraid of, such as ones about sexuality, democracy, religious expression, and Taiwanese independence?

So far, the answer has been yes. China's Internet is the most efficiently censored in the world. From a computer in China, try to visit the Web site of the banned activist organization Human Rights in China, based in New York City, and your request will be blocked by filters in the network.

Instead of the group's home page, you'll get an innocuous error message such as "File not found." Hundreds, maybe thousands, of sites are similarly blacklisted. The exact number can't be determined and changes daily.

Now China's experiment in cyberspace censorship is about to take a dramatic turn. A massive upgrade to the country's Internet will soon give China a robust, state-of-the-art infrastructure easily on a par with any in the developed world. China Telecom Corp., in Beijing, is investing US $100 million in what it calls the ChinaNet Next Carrying Network, or CN2.

The former national telephone monopoly is snapping up new network routers from four of the largest telecommunications equipment companies in the world: Cisco Systems and Juniper Networks of the United States; the French giant Alcatel; and Huawei Technologies, the only Chinese company to get a CN2 contract. During the next 12 months, the routers—the vertebrae of an Internet backbone—are to be installed in 200 cities throughout China's 31 provinces, autonomous regions, and municipalities.

Few doubt that China will emerge as a 21st-century global power. The questions now are about when it will emerge and what kind of power it will be. The issue of how China continues to censor its Internet, even as its infrastructure becomes vastly more sophisticated, has implications beyond what ideas China's populace—almost one-fifth of humanity—will be allowed to tap into. For one thing, if censorship technology flourishes in China, it will be easier and cheaper for it to also take root elsewhere. "The concern I have is that this is laying the foundation for a much more intrusive and censorship-friendly Internet infrastructure for all countries," says Roger Clarke, a consultant in Canberra, Australia, affiliated with the Australian National University. "The features that China wants installed in intermediating devices and software will gradually find their way into all of the suppliers' products, if only because it's cheaper that way."

Whether China's Internet censorship continues at the same level or—with its powerful new equipment—increases will probably play a significant role in answering the "What kind of global power?" question. Experts say that up to now, there have been technological constraints on the amount of censorship possible at the router level. In the network now taking shape in China, those constraints will be largely eliminated, making censorship more a matter of politics than of technology. Given the choice, will China move toward the openness of, say, South Korea? Or will it become something not yet seen in the postindustrial age: a closed capitalist colossus? No one now can say.

China's telecom and Internet infrastructure already is so mammoth, the authorities must wonder if they can really control it. China Telecom is the largest phone company in the world, with about 190 million users. Its ChinaNet subsidiary is the country's biggest Internet service provider. Almost 100 million Chinese are online, and analysts predict the number will triple by 2008.

All that traffic has outpaced capacity, so China's Internet is now a bottleneck to the country's massive push toward greater industrialization. Without state-of-the-art phone and Internet networks, the myriad routine exchanges that keep a technology-based economy humming start to break down. Bank fund transfers are slower and less reliable, videoconferences falter, and e-mail gets lost. Supply chains become weaker for importers such as Wal-Mart Inc., in Bentonville, Ark., which bought $18 billion worth of goods last year from thousands of Chinese suppliers, and for exporters such as the Haier Group, in Qingdao, which sells its refrigerators and other appliances in 160 countries.

But the Internet in China, as it is everywhere, is more than a development tool. It's also the main medium for political speech, organizing, and social networking.

"It's a dilemma for the Chinese leaders," notes Xiao Qiang, who left China after the 1989 Tiananmen Square pro-democracy uprising and now directs the Berkeley China Internet Project at the University of California at Berkeley's graduate school of journalism. "On the one hand," Xiao says, "they need a competitive economic development environment, and you cannot do that without the latest communications technologies—they are indispensable for a globally competitive economy. On the other hand, there's the explosive nature of communications technologies, which cause much greater freedom of expression."

Today, a vast, sophisticated, and multifaceted program of control has evolved to monitor China's Internet. It blocks access to banned sites and uses a long and continually updated collection of keyword filters that prevent Chinese citizens from viewing sites deemed pornographic or subversive. In addition, Internet service providers and Internet cafes [see photos, "Cafe Society"and "China Online"]. are subject to numerous state regulations. Tens of thousands of dedicated "Internet Police" reportedly do nothing but enforce those regulations, a special police force that has no parallel elsewhere in the world.

Yet, in the shadowy struggle that Internet censorship has become, the censors' first line of defense will surely be the routers and other machines that filter what Chinese users can see online. As the flow of data coursing through China's Internet becomes as wide as the Yangtze River, the government will need to raise its barriers to free speech to the height of the Three Gorges Dam.