Gradually, with hardly anyone noticing, President Chen Shui-bian of Taiwan has emerged as the most influential player in the volatile triangle of relations between China, the United States and his own island nation.

The reason: The Chinese are stuck with a rigid "one China" policy that shows no inkling of imagination or flexibility, and the Americans are paying only sporadic attention, hoping that the issue will somehow go away. That leaves Chen latitude to maneuver between them.

Even so, the chances of a miscalculation by Chen -- or the Chinese or the Americans -- continues to make the future of Taiwan the most dangerous long-term confrontation in Asia. One slip and hostilities across the Taiwan Strait could erupt to drag the U.S. and China into a disastrous war.

The standoff begins with Beijing's relentless claim that Taiwan is a province of China, and its insistence that the Taiwanese accept that demand. The Chinese have repeatedly threatened to use military force to conquer Taiwan if the Taiwanese declare independence or delay unification.

In pursuing that claim, Chinese leaders are boxed in by all manner of problems. Beijing seems to realize that attacking Taiwan would incur devastating economic losses. And China's military leaders, after years of brushing off the U.S. commitment to help defend Taiwan, have evidently begun to realize the potential U.S. military role in the defense of Taiwan.

In Washington, the Bush administration, preoccupied with Iraq and Afghanistan and the war on terror, has no long-range objective in its China or Taiwan policy. In recent weeks, President George W. Bush has concentrated on patching up relations with traditional allies and running for re-election against Sen. John Kerry, the presumptive Democratic nominee from Massachusetts.

Nonetheless, American military officers have quietly expanded their contacts with Taiwan's armed forces, sending observers to Taiwanese war games to learn their strengths and weaknesses and how U.S. and Taiwanese forces might mesh their operations in the event of hostilities between China and Taiwan.

The U.S. officers have also continued to have limited contact with Chinese officers in an effort to deter them. In a private exchange, a senior Chinese officer harangued his American counterpart about how China would brook no foreign interference on the issue of Taiwan.

To which the American replied dryly: "In the Pacific, we own the sky and we own the water," meaning air and naval supremacy, "so let's talk about something else."

In this precarious equation, Chen has been building a consensus at home intended to sustain Taiwan's continued separation from the mainland -- without a formal declaration of independence.

Taiwanese suggest -- and the polls bear them out -- that there is a widening consensus on maintaining the status quo, meaning de facto independence. "We are already a sovereign, independent nation," says a Taiwanese. "To declare independence means to declare independence from something. There's no need for that."

Former President Lee Teng-hui and Chen have taken the same position. In his address in May to inaugurate his second term, Chen took a firm but conciliatory approach toward China. "If both sides are willing," he said, they "can seek to establish relations in any form whatsoever."

In Beijing, the new regime of President Hu Jintao is stuck on dead center because it is beset by the former leader, Jiang Zemin, who is still chairman of the regime's military commission, and the People's Liberation Army. Hu thus cannot show himself to be weak on the Taiwan issue.

Hu is further hemmed in because hostilities with Taiwan and the U.S. would severely damage the trade and foreign investment vital to a China with 300 million unemployed or underemployed people -- 40 percent of the labor force. Last year, China exported $152 billion worth of goods to the U.S., its biggest export market.

In addition, Bloomberg News has reported that China has accumulated $527 billion in foreign investment and has another $1 trillion contracted. The U.S., Japan and Taiwan are the largest foreign investors in China -- and that would disappear in a war.

Several years ago, many Chinese asserted that the U.S. would not defend Taiwan. That notion has changed, as the Defense Department said recently: "Beijing sees Washington as the principal hurdle to any attempt to use military force to regain Taiwan."

Robert Sutter of Georgetown University in Washington D.C. agrees: "The U.S. is seen by Chinese officials as the dominant power in Asian and world affairs, and the main potential international danger to confront and complicate China's development and rising power and influence."