Washington

Scientific leaders are increasingly fearful that tighter immigration procedures, introduced in the wake of the terrorist attacks on 11 September 2001, are threatening the United States' position as a magnet for the world's scientific talent.

Researchers from countries as diverse as Indonesia and Germany are now subject to detailed security checks and rigorous interviews. The clampdown covers first-time visitors to the United States and those returning to lab positions there — delaying trips by weeks or months, and deterring some from coming at all.

The consequences of the change, which intensified with the introduction last August of new visa guidelines for consular officials, could be far-reaching. “We are in a rapid transition, whereby the United States will cease to be the destination of choice for researchers,” predicts Irving Lerch, director of international affairs at the American Physical Society.

Some researchers and officials outside the United States — such as those at top European universities — acknowledge that they could benefit from a protracted reduction in the flow of scientists into US institutions. But publicly, at least, they draw little comfort from the situation.

“I'd prefer a world in which individuals make free decisions about where to go and work,” says Robert May, president of Britain's Royal Society. “We need to keep Britain and other European destinations attractive for scientists — but not as second-choice countries.”

Last week in Congress, the House Science Committee held hearings to address scientists' concerns. “The current situation is untenable,” argued the committee's chairman, Sherwood Boehlert (Republican, New York). “Foreign students fill our graduate programmes; foreign scholars fill our faculty and laboratory positions. These people are a vital source of new ideas and perspectives.” But not all committee members agreed, with some voicing satisfaction at the exclusion of foreign scientists (see Congressmen unmoved by foreigners’ plight).

The overall scale of the shift is difficult to quantify, but some indicators suggest that it is significant. At the Human Frontier Science Program, which funds international collaborations between biologists, for example, the percentage of fellowship applicants who want to work in the United States has fallen from 75% in 2001 to 55% this year.

“The arbitrariness of the US immigration machinery has increased to a disturbing degree,” laments Erwin Neher, director of the Max Planck Institute of Biophysical Chemistry in Göttingen, Germany, who won the 1991 Nobel Prize in Medicine for his work on ion channels in cells. Several foreign scientists at the institute — from countries such as South Korea, India and Hungary — and at the nearby European Neuroscience Institute have been refused US visas altogether, Neher claims. “It is awful”, he says. “Our PhD student exchange programme with Stanford University is suffering badly.”

US research programmes, such as that of the Center for Nonproliferation Studies in Monterey Bay, California, are also feeling the pinch. Several researchers from the countries that the centre needs to work with, including China and parts of the former Soviet Union, have been denied entry to the United States. “I'm supportive of greater controls, but they are using a very blunt instrument and they are weeding out the wrong people,” argues Clay Moltz, a project director at the centre. Before 11 September 2001, Moltz says, he could usually talk to the US embassy in the country concerned to move an application along. Now the embassies don't return his calls. “There is no communication at all. You file these things and wait,” he says.

Also affected are public-health programmes, particularly those aimed at tackling infectious diseases such as HIV. Chris Beyrer, who directs the AIDS International Training and Research Program at Johns Hopkins University in Baltimore, Maryland, says that visa delays have occurred in all of the dozen or so countries with which his programme deals. Practically every applicant from China, where HIV is rapidly taking hold, has encountered long delays, he says. US embassies in Uganda and Thailand are entirely rejecting visa applications from about 1 in 10 of those seeking training at Johns Hopkins, Beyrer says. “We need to train scientists in Africa, and some of them have to get to the States,” he says. “Antiviral therapy for AIDS is not something you can learn from a handout.”

Visitors to the United States have faced tighter entry controls ever since the 2001 terrorist attacks, but the problems intensified last August, when the Department of State broadened its guidelines covering visiting researchers from “sensitive countries” to encompass those from all destinations. Under the guidelines, candidates for work and study visas whose applications mention any of a wide range of topics — including chemical engineering, biochemistry and microbiology — face possible interviews by consular officials (see Physicist discouraged by heightened security).

After these interviews, officials can elect to send the application to Washington DC for an interagency security review. Hundreds of scientific applications have been referred for such reviews, partly because consular officials lack scientific training. And with several agencies — including the Federal Bureau of Investigation, Central Intelligence Agency, Department of Homeland Security and Department of Defense — having to check each case, this process can take months.

“I'm aware of the problems, and I think they are serious,” says John Marburger, President George W. Bush's science adviser. Marburger says that his staff at the White House Office of Science and Technology Policy is meeting “almost every day” with agencies throughout the government to speed up the visa process. Marburger hopes to streamline the reviews, and to involve more scientifically qualified people in them. “I think we can do a better job without increasing the risk of terrorism,” he says.

But most observers don't expect the situation to improve any time soon. The United States' top priority is national security, points out one official in the Department of Energy, who works with visa applications. “No one wants someone to point a finger at them and say 'You just caused the death of 3,000 Americans',” the official says.

Additional reporting by Quirin Schiermeier in Munich and Jonathan Knight in San Francisco.