When British Prime Minister Neville Chamberlain sought to appease Adolf Hitler by standing aside while German armies invaded Czechoslovakia in 1938, the prime minister justified his decision in a radio address, saying it was horrible that Britain should consider going to war "because of a quarrel in a far-away country between people of whom we know nothing."

Today, history may be repeating itself, with China threatening to use force to conquer Taiwan, the self-governing island over which Beijing claims sovereignty. American support for far-away Taiwan is dwindling, making it possible that the U.S. might not help defend it against China.

Consider the change in President Bush's stance. Shortly after he took office in 2001, Bush told an interviewer the U.S. would do "whatever it takes" to protect Taiwan. "Our nation will help Taiwan to defend itself," he declared.

In an address in Prague last month, however, the president praised Taiwan and South Korea for marching toward democracy. But he said not a word about the U.S. helping to defend Taiwan against a China that has said repeatedly it would use force if Taiwan did not submit peacefully.

This turnabout has been several years in the making. Three years ago, Ted Galen Carpenter, of the Cato Institute in Washington, wrote an assessment in an echo of Neville Chamberlain:

"No reasonable American would be happy about the possibility of a democratic Taiwan being forcibly absorbed by an authoritarian China, but preserving Taiwan's de-facto independence is not worth risking war with a nuclear-armed power capable of striking the United States."

Those who doubt the willingness of the U.S. to defend Taiwan point to blood and treasure spent in the unpopular war in Iraq. Even though the U.S. could confront China with naval and air power, they argue, polls indicate that political support would be lacking.

Further, they point to China's rise as a political and military power that must be reckoned with, and the fear of China in other Asian nations. And they point to the economic intertwining of the U.S. and China. In 2006, China was the second-largest source of imports into the U.S. (after Canada,) and the fourth-largest market for U.S. exports, (after Canada, Mexico, and Japan).

Political leaders in Taiwan, notably President Chen Shui-bian, have not helped their own cause. Chen stirred the wrath of both Beijing and Washington recently by announcing he would hold a referendum to build domestic support for a proposal that his government apply for United Nations membership using the name Taiwan.

While the application would be blocked by China, an affirmative vote in the referendum would underscore Taiwan's drive for independence — and erode China's claim to the island.

The State Department immediately reflected Bush's displeasure: "The U.S. opposes any initiative that appears designed to change Taiwan's status unilaterally."

The department added: "Such a move would appear to run counter to President Chen's repeated commitments to President Bush" not to press for independence.

Taiwan has also lost U.S. support by appearing to be unwilling to defend itself. Taipei has dithered over the purchase of a large arms package that Bush offered, and U.S. military officers have said that Taiwan's forces, while improved, have been slow to modernize.

The consequences of U.S. failure to defend Taiwan would be profound. Said an experienced China watcher: "There is no upside to this." Acquiescing in China's takeover of Taiwan would: