When ten new member nations officially became part of the European Union (EU) earlier this month, it added a huge number of new recruits — and opportunities — to the region's scientific job market. But this expansion will require recruiters across the EU to strike a somewhat delicate balance. How, for example, can the wealthier EU nations in the west absorb thousands of scientists from the poorer new members without stretching their own resources and without draining the eastern countries of their intellectual capital?

The west should certainly prove to be a big draw for researchers in the east. The Baltic nations have a tradition of rigorous training in maths, physics and chemistry. These skills are in short supply in the west, so promising students could well find themselves wooed with promises of more funds and better infrastructure. Indeed, the west has regularly looked east for such skills, but EU membership changes the rules for visas and improves mobility.

This increased mobility carries with it the threat of an east–west brain drain. With some prudence and creativity, this could be avoided. One approach is to set up networks, such as ScanBalt, that emphasize collaborations between the east and west. Alternatively, efforts that encourage researchers within the eastern nations can help to persuade them to stay at home. For example, last summer, the medicinal-chemistry department at the University of Szeged in Hungary held a symposium that paired undergraduates with more senior scientists in a bid to give the youngsters more chances to publish.

Sadly, it is inevitable that many young scientists from the new member states will head west to seek their fortune. Hopefully, this will lead to a strengthening of infrastructure and investment in the new members that will eventually draw them, and others, east.