US visa crackdown disrupts meetings
Most heavily affected so far have been scientists from China and the former Soviet Union, who are involved in weapons research or other areas sensitive to national security.
Ironically, the new security measures could have negative impacts, making it more difficult for US government scientists to develop with non-proliferation programmes with the help of foreign researchers, and to discuss with them how to protect civilian populations from terrorist acts.
Routine scientific exchanges appear to be less affected by the additional security, however, with the US National Science Foundation reporting that its collaborations with foreign scientists have been unaffected.
Link to full Science news article
Source: Science 297, 1259 (2002)