Under a new screening program that went into effect in Britain last week, graduate students from outside the European Union and the European Economic Area must obtain a special security clearance before applying for a visa if their field of study falls within one of the 41 disciplines that the government has deemed “sensitive subjects.” Those include science, engineering, or technology-related disciplines, such as aerospace engineering, metallurgy, veterinary sciences, and agriculture.

The program, known as the Academic Technology Approval Scheme, or ATAS, is part of an international effort “to stop the spread of knowledge and skills that could be used in the proliferation of weapons of mass destruction,” a government Web site explains.

Some researchers have expressed skepticism about the plan. “This is not a very intelligent scheme,” Peter Littlewood, chairman of the physics department at the University of Cambridge, is quoted as saying in an article published online Wednesday by the journal Nature. “It seems unlikely to make a positive contribution to security, and for most students will be an extra hoop to jump through that will encourage them to go elsewhere.”

The new program replaced a voluntary system under which universities alerted authorities at their discretion. Some scientists voiced concerns about the new system long before it was introduced. “An overzealous replacement” for the voluntary program could have negative effects on Britain’s economy and on “its reputation as one of the most attractive places for students to study abroad,” a spokeswoman for the Royal Society, the nation’s leading scientific organization, told the BBC News last March.

Nature’s article notes that when the United States introduced similar measures in the wake of the September 11, 2001, terrorist attacks, the resulting delays in processing visas were blamed for a drop in academic traffic to American institutions.

The British-government site assures applicants that they will not face undue hurdles. Because the new program “is targeted at only a small range of sensitive subjects,” it says, “it is more streamlined and much faster than similar schemes in other countries. The vast majority of ATAS applications will be processed within 10 working days from the date we receive them.” —Aisha Labi