When Chatichai Choonhavan, prime minister of Thailand, visited Washington last week, he found that American officials had more on their minds than the military and political issues that for decades have dominated relations between the two countries.

In meetings with his delegation, the Americans stressed that Thailand had to act decisively to reduce its $2 billion a year trade surplus with the United States.

A decade ago, only the bravest of futurologists would have predicted that Thailand, a nation of rice farmers, would face this particular problem with its ally across the Pacific. But in the late 1980s, it emerged as one of the world's most dynamic growth economies. Exports boomed as Thai factories churned out shiploads of traditional products like textiles while moving up the technology ladder into computer components and consumer electronics.

Thailand thus becomes the latest country in the Pacific rim to find that economic progress can forever alter its ties with the United States.

"Whenever we find a new country that has a surplus with us," said Richard Drobnick, director of the international business education program at the University of Southern California, "they're going to get our attention. It went from Japan, to Taiwan, to Korea and now to Thailand."

However, standards of living remain well below those of the other wind-sprint economies of the Pacific. And some Thai officials worry that the boom is not nurturing much home-grown expertise. But few would turn back the clock.

With the growth -- 11 percent last year, the highest in Asia -- has come confidence in the future and willingness to part ways with the United States on political issues if necessary. Probably most important is its decision to open a dialogue with the Hun Sen government of Cambodia in an effort to settle the civil war there.

U.S. trade negotiators have focused on pressuring Thailand to give greater protection to "intellectual property." Unauthorized copying of movies, computer software and designer fashions is big business there.

Legislation is now before the Thai parliament to strengthen its anti-piracy laws, and Thai officials promise better enforcement. "We have done everything as we promised," said Surakiat Sathirathai, economics adviser to Chatichai.

Some Americans aren't so sure, though. Tom White, president of the Thai branch of Phelps Dodge Corp., suggests Thailand is dragging its feet and still sees itself as poor enough to justify pirating foreign creations.

Access for U.S. cigarette makers to the Thai market, which is controlled by a government-owned monopoly, is another point of friction.

Despite disputes like these, the overall relationship remains solid, U.S. officials stress. "We are experiencing a very exciting time," said Jon M. Huntsman Jr., deputy assistant secretary of commerce for East Asia and the Pacific. "There is a great deal of excitement among the U.S. business community."

U.S. companies use Thailand as a mass production site, taking advantage of low wages and a motivated work force. But Japanese and Taiwanese companies are well ahead in total investment there, as they shift production overseas.

During his visit here, Chatichai called on U.S. investors to close the gap. "The United States technology is second to none," he told George Bush in a farewell speech on the White House lawn on Thursday. "And so United States investment should be second to none." It was another sign of the changing times -- Thailand chiding America for not trying hard enough.