Ideas can travel the world instantly, but the movements of those who develop them are being restricted. The US is shutting its doors to scientists from 'terrorist-friendly states', reports Steve Farrar.
The first academic meeting that Mohamed Hassan missed was scheduled for August. This was three months after he made the trip across northern Italy from his office in Trieste for a visa application interview at the US consulate in Milan.
August came and went and despite regular calls by his staff, consulate officials explained they were still awaiting clearance from Washington to allow the Sudanese-born chief executive of the Third World Academy of Sciences to enter the country.
Hassan, a mathematician, was perplexed. He had been a regular visitor to the US since moving to Italy 13 years ago to head the internationally respected organisation. In this role, he had addressed top scientific conferences, spoken at world summits and even shaken hands with George Bush senior when he was president of the US.
But Hassan's Sudanese nationality, not previously an issue, has now become a problem. The country of his birth is considered by the US to be one that harbours terrorists, and its citizens are believed to be potential threats to security.
Despite his frequent visits, high status and impeccable academic record, it seems he can no longer expect to be welcomed in the land of the free. In the immediate wake of the 9/11 terrorist attacks, Hassan managed to get a new one-year multiple-entry visa, though passing through immigration control became a 90-minute ordeal of being fingerprinted, photographed and "treated like a criminal".
But when it came to his next visa, a fresh wave of restrictions and practices kicked in. The new requirement of an application interview was inconvenient and a bit humiliating, but Hassan was well known to consulate staff and so it proved rather perfunctory.
The unexpected delays that have followed, however, have left him baffled.
In October, Hassan was to deliver a report to a meeting of a World Bank consultative group in the US. Still without a visa, he had to cancel.
In November, he was due to meet with representatives of the US National Academy of Sciences in Washington and deliver a lecture at the prestigious annual meeting of the Sigma Xi scientific research society. He was forced to miss both.
"I'm really curious to know why it's so difficult," he says. "It seems they do not use any sort of screening. The damage caused by these delays works in both directions - for the individual who is not getting to participate in important events and also for the US scientific enterprise, which loses beneficial connections abroad. These delays are definitely affecting the future of scientific collaboration with the US."
Just before Christmas, Hassan called the consulate himself to ask what the problem was. US officials assured him they had not forgotten his application, but that Washington had not approved the application yet.
Eight months on, there is still no news.
Hassan's experience is extreme but not unique. Growing numbers of academics from China to Iran tell similar stories.
In the past few years, as the US government has pursued war on terror at home and abroad, foreign nationals have found it increasingly difficult to get into the country.
Those who require visas are confronted with an application process that is ever more tortuous and drawn out. As a result, academics from a host of nations are finding their efforts to get to major international meetings - often staged in the US - hamstrung by bureaucracy and delays. Many are forced to ditch their plans. Others do not even bother to apply.
It seems that the US government's attempt to build a wall around the nation to protect it from terrorists is also keeping out members of the academic community. A year ago, the presidents of the US national academies of science, engineering and medicine issued a joint statement warning that:
"Recent efforts of our government to constrain the flow of international visitors in the name of national security are having serious unintended consequences for American science, engineering and medicine."
They wanted to see qualified scientists welcomed into the country, insisting this would help harness international cooperation for the fight against terrorism, strengthen allies to tackle global problems and maintain US leadership in science.
Instead, the presidents complained that research collaborations had been hampered, young scientists were being delayed or even prevented from entering the US to study and important international conferences cancelled because of the difficulties foreign delegates were encountering.
The plight of foreign students prompted widespread indignation and calls for action from US academics. The blight on conferences, which foster new ideas and collaborations, has received much less attention. But its significance is serious nonetheless.
The national academies' presidents were clear: "If we continue to exclude foreign researchers from conferences held in the United States, then those meetings may cease to take place in this country in the future, depriving many American scientists of the opportunity to participate in them."
Stripped of important contributions from overseas, a host of US conferences have already been hit.
Large Russian and Chinese delegations were prevented from attending the World Space Congress in Houston in 2002, and some 25 Chinese delegates and exhibitors expecting to travel to last year's Association for Asian Studies annual conference in New York did not receive their visas in time.
A US government-supported meeting that was to discuss the situation in Afghanistan was thrown into disarray when invited Afghan academics were denied permission to enter the country.
The Lepton Photon Symposium, which is staged annually at venues around the world, was held at the Fermi Lab near Chicago last year. The number of Russian scientists attending was practically half that of the previous year, and the Chinese delegation was reduced to just one man.
Hesheng Chen, director of the Institute of High Energy Physics in Beijing, got his visa approved but too late to make the trip.
Vera Luth, chair of the commission on particles and fields of the International Union of Pure and Applied Physics (IUPAP), says of that debacle: "Realising that the chances of obtaining approval in time were slim, many of the invitees withdrew their applications; others did not want to subject themselves to the application process."
Helen Quinn, president of the American Physical Society, says this has prompted serious talk about whether future IUPAP meetings should be staged in the US. "So far they have not taken that step, but I believe that they will do so if things do not improve soon," she says.
Creeping US isolation worries Quinn. "Science today is very international and one must be 'in the loop' with the best people all over the world to be at the forefront," she says. "We cannot shut ourselves off from the rest of the world without paying a very heavy price. I recognise that there were indeed major security holes in the way visas were granted in the past and that these need to be fixed. However, we need a system that takes into account the pluses of international flow of information as well as the minuses."
The extent to which that flow has been restricted is merely hinted at by the figures gathered by the national academies' international visitors office. As of January 9, the office had handled 873 cases in which there had been problems getting into the US to study, carry out research or attend meetings. In 521 cases, the result was successful. But 288 were still being pursued with individuals having waited five months on average.
Wendy White, director of the US national academies' board on international scientific organisations, says: "The bulk of the problems we hear about are with China and Russia, and there are some cases from India. But my suspicion is that few scientists from the Middle East are even trying - they feel defeated before they start."
Some have left too little time for applications to be processed - White recommends at least six months. Most, however, have fallen victim to a breakdown in the system.
Consulate staff are now in effect policing US borders. They have been told that they will be held personally responsible if someone whose entry they approved subsequently turns out to be a threat. With vast numbers of cases to deal with, the inclination is to err on the side of caution or to delay making a decision. "No one wants to make a mistake," White says.
She was recently in China, where she met academics frustrated by the delays. She says: "This is a unique situation for many scientists. They feel they are being singled out for punishment, and it is very hard for them to understand that it is a broad-brush treatment that affects everyone."
In an effort to speed things up, the national academies are working with the US government to register major academic meetings online so that credentials can be checked more easily. There are plans for a similar initiative to record major international scientific collaborations.
Professional societies are even exploring the possibility of the scientific community sharing the burden of vetting foreign delegates to speed visa applications.
But White fears that the damage may already have been done. The overall number of visa applications has slumped by more than a quarter in the past two years, and scientific organisations are considering moving major conferences outside the US. "We are worried that what may be a blip on the radar now might have a huge impact in the future," she says.