Layovers between flights are always a drag, but Taiwan's PRESIDENT CHEN SHUI-BIAN discovered last week that they can also be an embarrassment. En route to Costa Rica and Paraguay, two of a dwindling number of nations hat still have full diplomatic relations with Taiwan, Chen wanted to stop over in San Francisco or New York City. While his plane refueled, he'd get to show the Chinese leadershipwhich views Taiwan as a breakaway provincethat he's welcome in the U.S., traditionally Taiwan's staunchest ally. But Washington, irritated by Chen's provocative stance toward Beijing, told him that only Hawaii or Anchorage, Alaska, were open to him. Affronted, Chen decided not to landed in the U.S. at all, taking instead a marathon route via Abu Dhabi and Amsterdam to Latin America. Washington appeared willing to slight Chen to placate Beijing, whose cooperation it needs on everything from reducing the U.S. trade deficit to reining in the nuclear ambitions of North Korea and Iran. Given China's growing clout, the world looks set to become an ever-smaller place for Taiwan