China used its legal system to seize two Chinese American scholars as hostages and then to free them as an offering to Colin Powell just before he visited Beijing last weekend. This is more than dictatorial business as usual. Beijing hides an important message in plain sight.

If you sit at the State Department, the cases of Gao Zhan and Li Shaomin may appear to be the Chinese Politburo's contorted way of making nice -- of trying to get the relationship "back on track" and giving a new secretary of state a sense of usefulness. So Powell had diplomatic grounds for shrugging off the incident, as he did once the two detainees were expelled and safely out of China.

But across the Potomac River at CIA headquarters near McLean, you might get a different perspective on the arrests of Gao, a researcher at American University and a legal U.S. resident, and Li, a business professor from Hong Kong and a U.S. citizen. They were convicted on trumped-up charges of spying for Taiwan after they collected routine research documents in China.

The message Beijing is sending to George Tenet and his Central Intelligence Agency is deciphered by other intelligence professionals thusly: Don't even think about it.

That is, don't try to use Chinese Americans or Taiwanese citizens who can move about unobtrusively in Chinese society for advantage in the world's most important spying contest. The subliminal message goes on:

"We know, even if hard-liners in Washington don't, that you have made stealing our secrets your top priority, and that you have been pretty good at it. We also know that we cannot count on this White House to cover up what you discover about our smuggling missile technology or whatever, as we could before.

"So we have to tighten even more the surveillance we have put around your embassy since the May 1999 bombing of our embassy in Belgrade. That has already reduced your capability. So did our successful interception of your EP-3 spy plane. These arrests of overseas Chinese visiting here should show you that in China, we know how to chop off the heads of a few chickens to frighten the monkeys."

Espionage, not diplomacy, has dominated U.S.-Chinese relations since George W. Bush came to the White House. Powell's mission in Beijing last week was to get the diplomats back in charge, at least on the surface, so they can smooth out the wrinkles that have developed and prepare a successful presidential visit by Bush in October.

To that end Powell put a temporary gloss on an unstable situation. (The spies will continue to be more decisive than the diplomats.) Even so, Powell's statements on human rights in Beijing were surprisingly soft, coming after the brutal and humiliating treatment of Gao, the researcher whose husband and 5-year-old child, who is a U.S. citizen, were detained along with her in February. The husband and son were subsequently released.

It was left to Benjamin Ladner, president of American University, to make the obvious point about the Chinese handling of Gao and other visiting academics: "How long can you maintain [a] cordial, friendly relationship on scholarly grounds, when they are trying . . . to make a very strong statement that they do not respect the rights of academic freedom?"

About 50,000 Chinese students go to American colleges today. That is an increase of 10,000 over the past 12 years, as U.S.-Chinese relations have steadily deteriorated. A more careful and vigorous screening of visas to weed out spies that Beijing has planted in the ranks of the students is an appropriate response to the targeting of Chinese American scholars by China's counterespionage.

Instead it looks like diplomacy as usual. Two days after Powell left Beijing, the United States signed a formal agreement with China resuming U.S. trade development assistance to Beijing. The assistance had been suspended after pro-democracy demonstrators were massacred in Beijing in 1989. The decision to resume grant assistance -- which will help China hoard its $180 billion in foreign reserves and the $110 billion it controls in Hong Kong's treasury -- was made by the Clinton administration in January and was allowed to go into effect this week by the Bush team.

Switch seats once again and go to Zhongnanhai, Beijing's equivalent of the White House. You down the U.S. spy plane and then bill Washington for holding the American crew prisoner. You arrest their citizens as political hostages. And they send over their secretary of state to praise you for trying to improve relations and then they resume financial assistance. Message: muscular works.