WASHINGTON (CNN) -- President Clinton's trip to China was originally meant to cap a thaw in relations between the world's most powerful country and the world's most populous nation.

And while the president finds himself dogged by questions about the transfer of missile technology to China and Chinese attempts to influence American elections, such controversies are unlikely to erode affairs between the two countries.

For one thing, China is now the United States' fifth largest trading partner. A good relationship with the Chinese not only keeps international anxieties down, it is also good for American business.

Exports to China account for approximately 170,000 U.S. jobs, and the White House says a breakdown in that relationship would cost U.S. consumers approximately $500 million a year in higher tariffs on such products as shoes and clothing.

More to the point, however, is Clinton's belief that a U.S. relationship with Beijing is the best way to influence China.

In a statement about Clinton's trip, the White House says human rights will be discussed at the summit. "Engagement does not mean endorsement," it stressed.

In fact, the recent release of two dissidents by the Chinese government, Wang Dan, a Chinese democracy leader, and Wei Jingsheng, appears to have been timed to smooth the way to the summit.

Wang was a student leader in the Tiananmen Square democracy protests in 1989, and there are plans for Clinton to visit the square during his stay.

There has been an outcry in the United States demanding that Clinton bypass the square, but in an editorial, The New York Times encouraged the president to seize the occasion for "a blunt speech about the value of freedom and human rights."

Such a speech would have been unthinkable a decade ago. Indeed, until 20 years ago the United States and China regarded each other as bitter enemies.

After Mao Tse-tung's Communists took over China in 1949, the United States came to regard the Communists as the devil incarnate, and often demonized "Red China."

When communism spread to other Asian countries, President Lyndon Johnson justified the war in Vietnam as an attempt "to help prevent Chinese domination over all of Asia."

Chinese-American relations didn't improve until the war ended, although President Richard Nixon privately signaled China that the United States would accept "peaceful coexistence" with the Chinese.

Mao in return said he would welcome a visit by the American president, and an exchange of table tennis teams broke the ice for Secretary of State Henry Kissinger to make a secret visit to Beijing in the summer of 1971.

Chinese troops crushed democracy demonstrations near Tiananmen Square in 1989

Nixon's trip to China in 1972 laid the foundation for the gradual improvement of Sino-American relationships. Even that relentless cold warrior Ronald Reagan said in 1984, "I remain confident that Chinese-American cooperation will grow and strengthen in the years ahead."

The years ahead, however, included the pro-democracy demonstrations in Tiananmen Square in 1989, and the massacre and imprisonment of hundreds, perhaps thousands, of people.

The episode sent Sino-American relations into a nose dive that the Bush administration tried to overcome with secret visits to Beijing. Nevertheless, when Clinton campaigned for the presidency, he promised that he had no plans to "coddle" dictators.

Perhaps the most forceful opponents of the thaw in Sino-American relations, however, have been human rights advocates. They accuse the Chinese leaders of ruthlessly exploiting their people and cynically manipulating international opinion with the occasional release of a dissident like Wang.

According to Human Rights in China, a private group based in New York, there are more than 150 Chinese still in prison for Tiananmen-related offenses.

Since becoming president, Clinton has found it preferable to engage the Chinese in dialogue on such issues as nuclear proliferation, human rights, peace on the Korean peninsula and the flow of missiles and weapons to the Middle East, where they might threaten the world's oil supply.

In other words, he prefers to work with the Chinese toward a more positive future rather than dwelling on the difficulties of the past.

Ralph Begleiter contributed to this report.