If, as seems increasingly likely, China embraces a trade regime that permits American firms to enjoy what our secretary of state terms "a fair field and no favor," how much does the United States stand to gain? According to the editorial pages of our most respected newspapers, senior government officials, captains of industry and numerous other opinion-makers, the answer to that question appears to be: much more than we can possibly imagine.

The chairman of a prominent U.S.-China business group, for example, contends that an accord will incalculably "strengthen and stimulate our trade" ties. A commercial roundtable claims that "no other market in the world offers such vast and varied opportunities for the further increase of American exports." Echoing these appraisals, the New York Times declares that it "is not our present trade with all Chinese ports, but the right to all that trade with its future increase" which for America will "become a source of great profit."

But the Times was wrong. For, as it happens, these optimistic predictions were being touted not in connection with the WTO negotiations of 1999, but rather in praise of the McKinley administration's Open Door notes of 1899. Indeed, today is hardly the first time we have heard testimonials about the magical powers of a trade compact with China. While myths about the China market predate the Renaissance, the present conviction that if only China "played by the rules"--that is, abided by Western trade practices--it would then blossom into a valuable market for American goods is exactly 100 years old.

Prompted by the misadventures of U.S. businessmen in China, the fear of surrendering market share to the European powers, and confident pronouncements about the "awakening of China," the Open Door notes of 1899 sought-much as the Clinton administration's WTO negotiators do--to establish equality of commercial opportunity for American investors in China, along with the elimination of arbitrary tax regulations and tariffs. The resulting elixir, it was claimed by the New York Times, meant that "anything produced in the United States will permanently find its way into all parts of the Celestial Empire." Other boosters argued that if every Chinese consumed one biscuit a day, American factories would have to run around the clock to meet the demand.

Alas, the facts were soon revealed to be otherwise. By 1900, Americans had invested only $17 million in China, as opposed to $185 million in Mexico. Cotton exports to China, which had tripled in the 1890s, collapsed during the next decade, and indeed, between 1905 and 1912, the value of total U.S. exports to China declined by half. Secretary of State John Hay's vision of "a fair field and no favor" had been realized, but China wasn't buying. A decade after the Open Door notes were issued, American exports to China still accounted for only 2 percent of total U.S. exports. And 2 percent is where that figure remains a century later.

Now, exactly how much faith we ought to put in the WTO accords is a question about which there is ample room for disagreement. But the cause of rational discussion has hardly been furthered by a new chorus of extravagant prognostications. "China is such a potentially huge market," exults a General Motors spokesman, "that if one percent of Chinese people could afford cars, that would be 12 million" cars. In the same vein, a parade of business groups has released "projections" that China's accession to the WTO will promptly yield untold billions in profits for American firms. Or as the late secretary of commerce, Ron Brown, put it, the PRC is "the pot at the end of the rainbow."

Having been so wrong before, are these voices right now? Perhaps, but many of the same barriers that survived the Open Door and proved so frustrating to American businessmen after 1899--arbitrary commercial laws, the absence of a proper regime to enforce them, bitter xenophobia and a destitute pool of consumers--will survive the WTO as well. Their persistence, in fact, recently prompted the International Trade Commission to predict that, rather than reducing our $57 billion annual trade deficit with China, a WTO accord may inflate the imbalance still further.

None of this seems to have made the slightest impression on the most ardent WTO enthusiasts, who have been touting its anticipated effect on China as if nothing has been learned, and nothing remembered. They would do well to cast a glance backward. For, as their predecessors of a century ago shortly conceded, opening the door to China is but a first step. Discovering a market on the other side is something else altogether.

The writer is executive editor of the National Interest.