Concerns in the United States that the next generation of terrorists will be recruited from eastern Europe have highlighted the main flaw in the established system of immigration screening, commonly known as racial profiling.
Following the terrorist attacks in New York and Washington on September 11, 2001, Arabs and Muslims have been targeted as potential threats to US security. All 19 hijackers and a man arrested before the attacks were Arabs.
Under the National Security Entry-Exit Registration System, all men over the age of 16 who are studying or working in the US on temporary visas, and come from 20 high-risk nations, must be fingerprinted, photographed and interviewed.
Human rights and legal groups have criticised the policy, calling it discriminatory. They say an unknown number of people have been illegally detained or deported, despite having valid visas.
The system is not new and was used most controversially during World War II after the Japanese attack on Pearl Harbour in 1941. Then, Japanese immigrants were forced to register and controversially put in detention camps until the war ended.
History had shown that such methods did not guarantee US security, according to Judy Golub, senior director of advocacy with the American Immigration Lawyers' Association.
'It's a false solution to a real problem,' Ms Golub said from her Washington office. 'It's not going to help us enhance our security. It's going to make us feel safe when we shouldn't.'
She said the registration system had not been well advertised and the registration requirements were unclear.
'The immigration service hasn't been given enough staff or resources to do a good job, and they're spending precious resources detaining and deporting people who have a claim to legal status,' she said. 'That's not a wise use of resources and it's not going to make us safer.'
The Association of International Educators, which represents professionals in student exchange programmes, has also campaigned against the policy.
Spokeswoman Ursula Oaks said the group was not opposed to the concept, but was concerned that it could become heavy-handed and violate individual rights.
The real problem may be far more fundamental. The targeting of people from the Arab and Muslim worlds ignores the fact that other races could carry out terrorist attacks.
The US government appears to have recognised this, although it has not made it a priority. Attorney-General John Ashcroft said on December 17 that all nationalities would eventually have to register, but he gave no timeframe.
As the US has the highest cross-border traffic of any country in the world - 500 million people last year - such a task would be beyond the capabilities of the present system.
John Keeley, of the Washington-based Centre for Immigration Studies, said that with the al-Qaeda terrorist network known to be recruiting fighters from the Russian province of Chechnya, immigration officers would soon need to be keeping watch on eastern Europeans. Caucasians would be as suspect as Arabs, making for a logistical nightmare.
'The strategy in place now will relatively quickly become outdated,' he predicted.
Mr Keeley said the US security problem lay with a lack of border controls. With just 9,000 immigration officers and only a fraction on duty at any one time to protect the 11,000 km-long borders, the scale of the problem was obvious.
'The government has shirked its responsibilities in securing the borders,' he said. 'It is now attempting to execute a war against terrorism, but it will be toothless unless something is done soon.'
Registering aliens was a fundamental endeavour to address the vulnerabilities, but was only the first of a number of steps. Key among these was employing more border patrol personnel and implementing a computerised and intelligence-linked entry and exit system. Congress was considering such a proposal and it seemed likely to be approved.
Mr Keeley also suggested that the US reduce the number of people it allowed to visit, because studies had proven that the number of illegal immigrants was proportionate to the number of those who entered the US legally.
Whether the US heeds the advice depends on its other costly obligations, such as an impending war on Iraq and tax reform. But the speed of change may also be dictated by another terrorist attack orchestrated from across frontiers deemed by experts and officials alike as porous.