Sir

In a recent Editorial, you describe the arduous visa requirements applied to students or scientists seeking to enter the United States (Nature 461, 12; 2009). I experienced similar challenges and more as an American applying for a student visa to enter the United Kingdom.

My permanent residency in Europe counted for nought. Bewildering tangle of directives? Check. Mysterious acronyms? Check. Proof of money to cover expenses? Check. Uncertain waiting times? Check. The UK visa system has requirements not (yet) dreamed of in the United States, such as a letter from the admitting university not only confirming that the student has been accepted but also detailing why. The exam scores or reference letters used in the admittance decision also have to be included in the application process.

It is not only the United States that needs to consider balancing the need for security with allowing students and scientists reasonable terms of entry to the country.