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Off limits: the Los Alamos National Laboratory in New Mexico, site of the recent controversy over the alleged theft of critical atomic secrets. Scientific societies in the United States see this as having accelerated a trend against allowing foreign scientists to work in ‘sensitive’ areas of research. Chinese-American scientists feel particularly vulnerable. Credit: LANL

Scientific societies in the United States are increasingly concerned that the US government has reversed its previous support of free communication between scientists. They claim there is now a policy of isolating scientists who come from countries to which it wishes to deny access to a range of new technologies.

The societies say, for example, that the State Department is dragging its feet in granting visitors' visas for foreign scientists wishing to attend conferences in the United States. At last month's meeting of the International Union of Pure and Applied Physicists in Atlanta, Georgia, for example, prominent physicists from China and Russia were excluded. Furthermore, the leader of the Indian delegation was only admitted after the personal intervention of Bruce Alberts, president of the National Academy of Sciences.

Irving Lerch, head of international affairs at the American Physical Society (APS), says the United States has reversed course since the last such conference was held here in 1987. Then, visits from Russian and Cuban scientists were welcomed. “Now the situation is quite different,” he says. For the State Department, Lerch says, “the most important aspect is to prevent technology transfer”.

The State Department has long been trying to curtail visits of scientists from so-called ‘rogue states’ such as Iraq and Libya. But it was in the aftermath of India and Pakistan's nuclear tests last spring that US scientific societies began to complain about its policies. They now fear that the clamp-down has been lent new impetus by recent allegations that a Taiwanese-born scientist was involved in a security breach at the Los Alamos National Laboratory (see Nature 398, 96; 1999 & Nature 398, 276; 1999).

The department also appears to be implementing its infrequently exercised right to vet immigrant visa applications from scientists in a wide range of disciplines. Last month, for example, Jianjun Hu, a Chinese materials scientist who has secured a position at Northwestern University, Illinois, had his visa application delayed in circumstances Lerch describes as “clearly fallout from the case at Los Alamos”.

The consulate to which Hu applied for a visa referred the application to the State Department on the basis that he would be working on “materials technology”. Northwestern expects Hu's visa to be approved within the next few days, a university spokeswoman says. Maria Rudensky, a spokeswoman for the State Department, said this was a well-established procedure. “Most scientists on our ‘technology alert list’ have to come through this,” she said.

The list covers some 20 disciplines, ranging from nuclear and missile technology to advanced computing, microelectronics and ‘biotechnology engineering’. It applies to scientists from an equally long list of countries, including Russia, China, Pakistan and South Africa — but not India. Rudensky said the two lists originate from the 1952 Immigration and Naturalization Act, but are updated at the State Department's discretion. She said she “didn't know why” South Africa — a democracy and an allegedly close ally of the United States — is on the list.

But Lerch claims that the implementation of these rules has changed. “There has never been a case quite like this,” he says about Hu's referral. The State Department, he says, “can turn these things on and off as they choose. It is very clear that there are a lot of people at the State Department who are suspicious of all of the physical sciences.”

“We're faced with a kind of hysteria,” he adds, contrasting the problems at this year's physicists' meeting in Atlanta with the last such meeting in the United States in 1987, when Ronald Reagan was president, and scientists from all countries were welcomed.

Scientists from countries labelled as ‘hostile’ who are already working in the United States have also felt the fallout from the Los Alamos case. However, they stress that it is the public mood, rather than the attitude of their scientific colleagues or managers, that worries them most.

“We would like to express our deep concern regarding the deterioration of the working environment of Chinese-American scientists and the scientific exchanges between the United States and China,” says a letter from Cheuk-Yin Wong, chairman of the 450-strong Overseas Chinese Physics Association, to APS president Jerome Friedman. The letter followed a discussion of 150 association members at the APS meeting in Atlanta and asks Friedman for a public statement of support for Chinese-American scientists.

Wong, a nuclear theorist at the Oak Ridge National Laboratory in Tennessee, is particularly concerned by media coverage of the Los Alamos incident. He cites an article in the 22 March issue of Newsweek, which described what it termed China's “vacuum cleaner strategy” for using Chinese scientists in the United States for espionage. “There are statements in that article that will lead the general public to question the loyalty of Chinese-American scientists,” Wong says.

Some press coverage has also suggested that many Chinese scientists are in the United States because the Chinese communist government wants them to take secrets back home. In fact, China has become the biggest single source of scientific immigration to the United States largely because the US Congress passed legislation in 1992 giving Chinese students special rights to stay after the crackdown against student demonstrations in Tiananmen Square.

Wong says that for Chinese-American scientists at the nuclear weapons laboratories “the environment is very nervous”. But at other government laboratories, and at universities where most Chinese-American scientists work, this recent spate of China-bashing may have little effect.

“I have plenty of good things to say about the system here,” says a successful Chinese-born chemist at one civilian Department of Energy laboratory. He notes that he “can't imagine the Chinese government doing the same” and allowing foreign scientists into its laboratories and universities. “It is true that people of my background have to work harder [than US-born colleagues], but I don't think that is necessarily unfair.”