“The storm center of the world has shifted … to China,” Secretary of State John Hay said in 1899. “Whoever understands that mighty Empire … has a key to world politics for the next five hundred years.” Well, everything is different and nothing has changed since Hay announced the famous Open Door policy, which demanded American commercial access in China equal to that of other major nations. A century of Sino-American ups and downs, with far more of the latter, followed, but today, in very different ways, the United States still seeks an open door; the secretary of the Treasury and an enraged Congress are hammering China to revalue its currency to give U.S. companies a better chance to compete with the world’s fastest-growing major economy.

Arguments over the exchange rate are a small part of what goes on these days between the two most important nations in the world. Washington and Beijing have several vital common interests, notably in the war against terrorism and the desire for strategic stability in the Pacific and South Asia. And the two nations are still making an effort to work together; on the American side, responsibility for what Washington calls “the global dialogue” is primarily in the hands of Deputy Secretary of State Robert Zoellick, who is planning a visit to Beijing soon.

But although both sides officially deny it, Sino-American ties are slowly fraying while other issues take up the attention of senior American officials. Beyond the never-ending Taiwan issue and Washington’s concern over China’s growing military muscle, two huge factors put the relationship under constant pressure: first, substantially different attitudes toward the rights of people to express themselves freely and, second, the massive trade imbalance. What vastly complicates U.S. relations with China is that every major foreign policy issue between the two countries is also a domestic matter, with its own lobbying groups and nongovernmental organizations ranging across the entire American political spectrum, from human rights to pro-life, from pro-Tibet to organized labor. The bilateral agenda, even a partial one, is daunting: Taiwan, Tibet, human rights, religious freedom, press freedom, the Falun Gong, slave labor, North Korea, Iran, trade, the exchange rate, intellectual property rights, access to Chinese markets, export of sensitive technology, and the arms embargo.

In Washington, where different parts of the executive branch dominate on each issue and Congress plays a major role, it can be difficult to stick to a coherent overall policy. China, on the other hand, with its highly secretive, tightly disciplined, and undemocratic system, can establish long-term policy goals and then work slowly toward them: The Chinese, are, as they like to remind visitors, a patient people. China’s advance toward long-term goals has produced extraordinary economic results since Deng Xiaoping’s reforms began in 1979, notwithstanding the terrible 1989 crackdown in Tiananmen Square. In foreign policy, however, things had been different until recently. After its war against Vietnam in 1979, China became defensive, even passive, on the world stage. But China’s new leaders have begun to match their economic power with a more assertive foreign policy. Taken individually, Chinese actions may look like a series of unrelated events. But they are part of a long-term strategy. Some recent examples:

* Premier Wen Jiabao’s self-proclaimed “historic visit” to India in April, during which the world’s two largest nations announced a “strategic partnership” – vague words, of course, that could mean almost anything, but quite different from those that have, over the past 50 years, characterized this tense rivalry (which included one war).

* President Hu Jintao’s stunning meetings in late April and early May with two top Taiwanese political leaders, marking the first such face-to-face meeting since Mao Zedong and Chiang Kai-shek met in 1945.

* The anti-Japanese riots in April, which could not have taken place without the acquiescence of the government. Ostensibly meant to protest Japanese schoolbook misrepresentations of World War II atrocities, the demonstrations were in fact a crude signal that no matter what China’s official position is, it does not really want Japan to become a permanent member of the U.N. Security Council.

* The highly unusual public criticism on May 12 by a Chinese Foreign Ministry official of American policy toward North Korea. Beijing is just plain tired of being called upon by Washington to salvage the six-party talks that North Korea has boycotted for almost a year, when, China says, there has been a “lack of cooperation from the U.S. side.”

* China’s intent – for the first time since Beijing took over the Chinese seat in the United Nations – to play a central role in the choice of the next U.N. secretary-general, who is slated, by regional rotation, to be from Asia. The new secretary-general, who takes office January 1, 2007, cannot be Chinese (no permanent member of the Security Council can have one of its own in that post). One leading candidate called on Secretary of State Condoleezza Rice this month, but Washington has not yet paid the issue enough attention.

* Finally, China has begun buying oil fields in such remote areas as Sudan and Angola, part of a long-term strategy to address its rapidly growing energy needs. With energy policy come major foreign policy interests; this is probably related, for example, to China’s reluctant attitude toward strong U.N. action in the Darfur region of Sudan.

China’s gradual emergence as a political player on the world stage comes when there is a growing impression among other countries in East Asia that Washington is not paying the region sufficient attention. (Ironically, this is in sharp contrast to India, where relations with the United States are at their historical best.) If we lose interest and political influence in the Asia-Pacific region just as it grows in economic importance, the imbalance will surely return later to haunt a new generation of policymakers – and the nation. The challenge is obvious, but the lack of clear focus at the highest levels in Washington on our vital national security interests in the region is disturbing.

Mr. Holbrooke served as assistant secretary of state for East Asian and Pacific affairs at the time of normalization of relations with China.