Bamboo curtain descends on dealings with foreigners

A Chinese writer recently invited a foreigner to his home, escorting him nonchalantly through the common courtyard past scores of staring eyes.

This writer, persecuted like many others during the 10-year chaos called the Cultural Revolution (1966-76), is so inured to the shifts in political line that have taken place during the past 30 years that he seems quite prepared for the next shift, whenever it may come.

''Just try to make sure that, when the line shifts, you don't shift with it. That's not always possible. But it's the only way, eventually, that a person can live with himself.''

The recent arrest and expulsion of Lisa Wichser, an American graduate student here in Peking, is a symptom more than a cause of a tightening of constraints on contacts between Chinese and foreigners.

Miss Wichser was accused of stealing secret government documents. The documents reportedly all had to do with the system of economic incentives and devolving of responsibilities in agriculture from the collective to the individual - hardly something to be classified as secret in other countries. Miss Wichser was using them in connection with a doctoral dissertation she was preparing on the subject. Who gave Miss Wichser the documents has not been made clear.

The incident made Chinese already nervous about meeting foreigners even more circumspect than usual. Restraints on Sino-foreign contacts have been in force at least since last autumn, when a party directive on the subject was circulated behind closed doors to Chinese citizens whose work generally brought them into contact with foreigners.

Since then, the appeal of a Chinese journalist against a five-year jail sentence for allegedly passing state secrets to foreigners has been disallowed. This information, supposedly about what went on inside a Communist Party Central Committee meeting on economic subjects, again is scarcely the kind of thing most other countries would consider classified.

While cracking down on these unauthorized disclosures, the government here says that its open-door policy toward economic and cultural ties with the outside world remains unchanged. This is the government's dilemma: It recognizes the importance of the open-door policy for the economic modernization China needs, but it is worried about the more open society these enhanced Sino-foreign contacts inevitably encourage.

As with so many other things in China, there is no flat ban on Sino-foreign contacts. The general atmosphere in China today is incomparably freer than it was during the Cultural Revolution. No one is talking about a return to the paranoia of those days.

On the other hand, if one fails to report a foreign contact, he may be in trouble with his superior, and his superior may be in trouble for failing to control his subordinates. For most ordinary citizens, caution and circumspection are the order of the day.