Tight anti-terrorism measures mean that postdocs and students travelling to the United States need to make plans a long way in advance and expect delays, says Karen Kreeger.

Each year, many young European scientists start postdoctoral work in the United States. But on completion, they can face difficulties in securing a position back home. Repatriated scientists, even when highly qualified, often lose out to better-connected internal candidates if they don't have strong backing within the department.